Covered prosthetic heart valve

ABSTRACT

A prosthetic heart valve includes a frame having an inflow end and an outflow end, and defining a longitudinal axis. The prosthetic heart valve further includes a leaflet structure situated at least partially within the frame, and a covering disposed around the frame. The covering includes a first woven portion extending circumferentially around the frame and including a plurality of texturized strands or yarns extending along the longitudinal axis of the frame. The covering further includes a second woven portion extending circumferentially around the frame and spaced apart from the first woven portion along the longitudinal axis of the frame. The texturized strands extend along the longitudinal axis of the frame from the first woven portion to the second woven portion and form a floating portion between the first woven portion and the second woven portion.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation of PCT Application No.PCT/US2019/014338, filed on Jan. 18, 2019, which is continuation-in-partof U.S. application Ser. No. 15/876,053, filed on Jan. 19, 2018, andwhich also claims the benefit of U.S. Provisional Application No.62/703,363, filed on Jul. 25, 2018. Application Ser. No. 15/876,053claims the benefit of U.S. Provisional Application 62/535,724 filed onJul. 21, 2017. Application Ser. No. 15/876,053 claims the benefit ofU.S. Provisional Application 62/520,703 filed on Jun. 16, 2017.Application Ser. No. 15/876,053 claims the benefit of U.S. ProvisionalApplication 62/449,320 filed on Jan. 23, 2017. Each of the foregoingapplications is incorporated by reference in their entirety herein.

FIELD

The present disclosure relates to prosthetic heart valves, and inparticular to prosthetic heart valves including a covering.

BACKGROUND

In a procedure to implant a transcatheter prosthetic heart valve, theprosthetic heart valve can be positioned in the annulus of a nativeheart valve and expanded or allowed to expand to its functional size. Inorder to retain the prosthetic heart valve at the desired location, theprosthetic heart valve may be larger than the diameter of the nativevalve annulus such that it applies force to the surrounding tissue inorder to prevent the prosthetic heart valve from becoming dislodged. Inother configurations, the prosthetic heart valve may be expanded withina support structure that is located within the native annulus andconfigured to retain the prosthetic heart valve at a selected positionwith respect to the annulus. Over time, relative motion of theprosthetic heart valve and tissue of the native heart valve (e.g.,native valve leaflets, chordae tendineae, etc.) in contact with theprosthetic heart valve may cause damage to the tissue. Accordingly,there is a need for improvements to prosthetic heart valves.

SUMMARY

Certain disclosed embodiments concern coverings for prosthetic heartvalves and methods of making and using the same. This summary is meantto provide some examples and is not intended to be limiting of the scopeof the invention in any way. For example, any feature included in anexample of this summary is not required by the claims, unless the claimsexplicitly recite the features. Also, the features described can becombined in a variety of ways. Various features and steps as describedelsewhere in this disclosure can be included in the examples summarizedhere.

In a representative embodiment, a prosthetic heart valve comprises aframe comprising a plurality of strut members, the frame being radiallycollapsible and expandable between a collapsed configuration and anexpanded configuration, the frame having an inflow end and an outflowend, and defining a longitudinal axis. The prosthetic heart valvefurther comprises a leaflet structure situated at least partially withinthe frame, and a covering disposed around the frame (e.g., around some,a portion, or all of the frame). The covering can comprise or be formedof a sealing member or cover member, which can be disposed around someor all of the frame to form some or all of the covering. In someembodiments, the covering and/or sealing member/cover member comprises afirst woven portion extending circumferentially around the frame andincluding a plurality of texturized strands (e.g., yarns, threads,sutures, or other elongated materials usable in a similar way to thosedescribed herein) extending along the longitudinal axis of the frame. Insome embodiments, the covering and/or sealing member/cover memberfurther comprises a second woven portion extending circumferentiallyaround the frame and spaced apart from the first woven portion along thelongitudinal axis of the frame. The texturized strands (e.g., yarns,etc.) extend along the longitudinal axis of the frame from the firstwoven portion to the second woven portion and form a floating portion,such as a floating yarn portion, etc., between the first woven portionand the second woven portion.

In some embodiments, the covering and/or sealing member/cover member isresiliently stretchable between a first state corresponding to theradially expanded configuration of the frame, and a second statecorresponding to the radially collapsed configuration of the frame.

In some embodiments, the floating portion/floating yarn portion isresiliently stretchable between the first state and the second state ofthe covering and/or sealing member/cover member.

In some embodiments, the texturized strands, such as texturized yarns,are configured to provide compressible volume to the floating portion,or to a floating yarn portion, of the covering and/or sealingmember/cover member when the frame is in the expanded configuration.

In some embodiments, the texturized strands (e.g., yarns, etc.) arewoven into a leno weave pattern in the first woven portion and in thesecond woven portion.

In some embodiments, the covering and/or sealing member/cover memberdefines a plurality of circumferentially spaced-apart openings.

In some embodiments, the openings in the covering and/or sealingmember/cover member overlie openings defined by strut members of theframe.

In some embodiments, the openings have been cut into a portion of thesealing member made of a bias cloth or bias fabric to inhibit frayingaround the openings.

In some embodiments, the covering and/or sealing member/cover memberfurther comprises a third woven portion on the opposite side of thefirst woven portion from the floating portion/floating yarn portion, thethird woven portion comprising the texturized strands/texturized yarnsof the first woven portion.

In some embodiments, the texturized strands/texturized yarns are woveninto a plain weave pattern in the third woven portion.

In some embodiments, the third woven portion is folded over apices ofstrut members at the inflow end of the frame.

In some embodiments, the covering and/or sealing member/cover memberfurther comprises a fourth woven portion on the opposite side of thesecond woven portion from the floating portion/floating yarn portion.The fourth woven portion comprises the texturized strands/texturizedyarns, and the texturized strands/texturized yarns are woven into aplain weave pattern in the fourth woven portion.

In some embodiments, the fourth woven portion comprises a plurality ofextension portions that overlie openings defined by the strut members ofthe frame when the frame is in the expanded configuration.

In some embodiments, the extension portions are tapered in a directiontoward the outflow end of the frame.

In some embodiments, the covering and/or sealing member/cover membercomprises a first protective portion folded over apices of the strutmembers at the inflow end of the frame, and the covering and/or sealingmember/cover member further comprises a second protective portion foldedover apices of the strut members at the outflow end of the frame.

In some embodiments, the frame is a mechanically-expandable frame.

In some embodiments, the frame is a plastically-expandable frame.

In some embodiments, the covering and/or sealing member/cover membercomprises a plurality of floating portions (e.g., floating yarnportions, etc.) spaced apart from each other along the longitudinal axisof the frame.

The floating portions or floating yarn portions can be heat set toobtain a desired size and texture, e.g., to make them softer and moretexturized.

The prosthetic heart valve can use twisted PET yarns in a warp directionand textured PET yarns in a weft direction. The twisted PET yarns in thewarp direction can be arranged to weave in leno pattern and the texturedPET yarns in the weft direction can form the floating yarn portionwithout any weave structure. The sealing members can be heat shrunk toachieve a stretchability between 80-160%. The frame can be amechanically-expandable frame with the above covering or sealing memberthereon.

The covering and/or sealing member can comprises at least one of alow-friction layer or low-friction coating on a least a portion thereof.This can include a low-friction layer over another layer of materialand/or low-friction strips or layer over portions of another layer. Thelow-friction layer or low-friction coating can be formed viaelectrospinning a low-friction material onto the frame or another layerof the covering and/or sealing member.

The prosthetic heart valve can also comprise strips of material that arehelically wrapped around struts and/or apices at one or both ends of theframe.

In another representative embodiment, a prosthetic heart valve comprisesa frame comprising a plurality of strut members, the frame having aninflow end and an outflow end, the strut members defining a plurality ofopenings in the frame at the outflow end of the frame. The prostheticheart valve further comprises a leaflet structure situated at leastpartially within the frame, and a covering disposed around the frame(e.g., around some, a portion, or all of the frame). The covering cancomprise and can be formed from a sealing member or cover member, whichcan be disposed around some or all of the frame to form some or all ofthe covering. The covering and/or sealing member/cover member defines aplurality of openings that are aligned with the openings in the frame.

In some embodiments, the frame comprises an outer surface, and thecovering or sealing member/cover member covers the entire outer surfaceof the frame.

In some embodiments, the covering and/or sealing member/cover membercomprises a first portion adjacent the inflow end of the frame includinga plush pile layer. The covering and/or sealing member/cover memberfurther comprises a second portion without a pile layer adjacent theoutflow end of the frame, and the second portion of the covering and/orsealing member/cover member defines the openings of the covering and/orsealing member/cover member.

The foregoing and other objects, features, and advantages of thedisclosed technology will become more apparent from the followingdetailed description, which proceeds with reference to the accompanyingfigures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic cross-sectional view of a human heart.

FIG. 2 shows a schematic top view of a mitral valve annulus of a heart.

FIG. 3 is a perspective view of an embodiment of a prosthetic heartvalve.

FIG. 4A is a cross-sectional side view of a ring anchor or dockingdevice deployed in a mitral position of the heart, with an implantedvalve prosthesis, according to one embodiment.

FIG. 4B illustrates a cross-sectional side view of an example of a coilanchor or docking device deployed in the mitral position of the heart,with an implanted valve prosthesis.

FIG. 4C is a perspective view of a representative embodiment of ananchor or docking device.

FIG. 5 is a perspective view of a prosthetic heart valve including arepresentative embodiment of a covering.

FIG. 6 is a side-elevation view of the prosthetic heart valve of FIG. 5.

FIG. 7 is a top plan view of the prosthetic heart valve of FIG. 5.

FIG. 8 is a cross-sectional side elevation view of the prosthetic heartvalve of FIG. 5.

FIG. 9 is a perspective view of a representative embodiment of acushioning layer including a plush pile.

FIG. 10 is a cross-sectional side view of the prosthetic heart valve ofFIG. 5 deployed in the mitral position of the heart.

FIG. 11 is a side elevation view of a prosthetic heart valve includingan example of a covering.

FIG. 12 is a perspective view of a backing layer, a stencil forproducing the backing layer, and a cushioning layer, before the backinglayer and the cushioning layer are secured together.

FIG. 13 is a cross-sectional side elevation view of a prosthetic heartvalve including an example of a covering.

FIG. 14 is a detail view of an inflow protective portion of the coveringof FIG. 13.

FIG. 15 is a side elevation view of a prosthetic heart valve includingan example of a covering comprising a spacer fabric.

FIG. 16 is a perspective view of a representative embodiment of a spacercloth including looped pile yarns.

FIG. 17 is a side elevation view of the spacer fabric of FIG. 16.

FIG. 18 is a top plan view of an embodiment of a backing layer after itis cut using a parallelogram stencil.

FIG. 19 is a perspective view of a prosthetic heart valve including anexample of a covering.

FIG. 20 is a side elevation view of the prosthetic heart valve of FIG.19.

FIG. 21 is a plan view of an outflow end of the prosthetic heart valveof FIG. 19.

FIG. 22 is a cross-sectional side elevation view of the prosthetic heartvalve of FIG. 19.

FIG. 23 is a top plan view of the covering of FIG. 19 in an unfoldedconfiguration.

FIG. 24 is a perspective view illustrating placement of the prostheticheart valve of FIG. 19 into the covering after the covering is formedinto a cylindrical shape.

FIG. 25 is a perspective view of the inflow end of the prosthetic heartvalve of FIG. 19 illustrating attachment of the covering to the strutmembers of the valve frame.

FIG. 26 is a perspective view of the inflow end of the prosthetic heartvalve of FIG. 19 illustrating a strip member of the covering folded overthe strut members of the valve frame to form an inflow protectiveportion.

FIG. 27 is a perspective view of a frame for a prosthetic heart valveincluding an example of a covering.

FIG. 28 is a cross-sectional side elevation view of the frame andcovering of FIG. 27.

FIGS. 29-31A are perspective views illustrating a representative methodof making the covering of FIG. 27.

FIG. 31B is a detail view of the electrospun layer of the inflow endportion of the covering of FIG. 31A.

FIG. 32 is a perspective view of a prosthetic heart valve including amain covering and a second covering extending over the apices of theframe.

FIG. 33 is a side elevation view of the prosthetic heart valve of FIG.32.

FIG. 34 is a plan view of a portion of the frame of the prosthetic valveof FIG. 32 in a laid-flat configuration.

FIG. 35 is a perspective view of the prosthetic heart valve of FIG. 32without the main outer covering.

FIG. 36 is a perspective view of the prosthetic heart valve of FIG. 32illustrating how the second covering is wrapped around the apices of theframe.

FIG. 37 is a perspective view illustrating the frame of the prostheticvalve of FIG. 32 including the second covering crimped onto a shaft of adelivery apparatus.

FIG. 38A is a side elevation view of the prosthetic valve of FIG. 19including an example of an outer covering.

FIG. 38B is a detail view of the fabric of the outer covering of FIG.38A.

FIG. 39A is a plan view illustrating the prosthetic heart valve of FIG.38A crimped onto a shaft of a delivery device.

FIG. 39B is a detail view of the outer covering of the prosthetic heartvalve in FIG. 39A.

FIG. 40A is a cross-sectional side elevation view of the fabric of theouter covering of FIG. 38A in a relaxed state,

FIG. 40B is a cross-sectional side elevation view of the fabric of theouter covering of FIG. 38A in a tensioned state.

FIG. 41A is a plan view of an example of a fabric outer covering for aprosthetic valve in a laid-flat configuration and including an outersurface defined by a pile layer.

FIG. 41B is a magnified view of the outer covering of FIG. 41A.

FIG. 42A is a plan view of a base layer of the outer covering of FIG.41A.

FIG. 42B is a magnified view of the base layer of FIG. 42A.

FIGS. 43-45 are a side elevational views of a prosthetic heart valveincluding various embodiments of an outer covering including openings.

FIG. 46 is a plan view of an example of a sealing member or a covermember for a prosthetic heart valve including woven portions andfloating portions configured as floating yarn portions.

FIG. 47 is a magnified view of a first woven portion of the sealingmember or cover member of FIG. 46.

FIG. 48 is a magnified view of a second woven portion of the sealingmember or cover member of FIG. 46.

FIG. 49 is a magnified view of a floating yarn portion of the sealingmember or cover member of FIG. 46 in a relaxed state.

FIG. 50 illustrates the floating yarn portion of FIG. 49 in a stretchedstate.

FIG. 51 is a plan view of the sealing member or cover member of FIG. 46in a stretched state.

FIG. 52 is a perspective view illustrating an edge portion of thesealing member or cover member of FIG. 46.

FIG. 53 is a side elevational view of a prosthetic heart valve having anouter covering including the sealing member or cover member of FIG. 46,according to one embodiment.

FIG. 54 illustrates the prosthetic heart valve of FIG. 53 crimped onto aballoon at the distal end of a delivery apparatus.

FIGS. 55A-55J illustrate various examples of leno weave patterns andleno weaving techniques.

FIG. 56 is a perspective view of a mechanically-expandable prostheticheart valve, according to one embodiment.

FIG. 57 is a side-elevation view of an example of amechanically-expandable frame for a prosthetic heart valve.

FIG. 58 is a plan view of an example of a sealing member or cover memberfor a prosthetic heart valve.

FIG. 59 is a magnified view of a portion of the sealing member or covermember of FIG. 58.

FIG. 60 is a side elevation view showing an example of a covering formedfrom the sealing member or cover member of FIG. 58 attached to the frameof FIG. 57 in the radially expanded configuration.

FIG. 61 is a perspective view of the inflow end portion of the frame andcovering assembly of FIG. 60.

FIG. 62 is a side elevation view of the frame and covering of FIG. 60 inthe radially collapsed configuration.

DETAILED DESCRIPTION

The present disclosure concerns embodiments of implantable prostheticheart valves and methods of making and using such devices. In oneaspect, a prosthetic heart valve includes a covering or outer coveringhaving a backing layer and a main cushioning layer disposed on thebacking layer such that the cushioning layer is oriented radiallyoutward about the circumference of the valve. The cushioning layer canbe soft and compliant in order to reduce damage to native tissues of theheart valve and/or of the surrounding anatomy at the implantation sitedue to, for example, relative movement or friction between theprosthetic valve and the tissue as the heart expands and contracts. Thecovering can also include an inflow protective portion and an outflowprotective portion to cushion the surrounding anatomy and prevent thenative tissue of the heart valve from contacting the apices of the strutmembers of the frame, thereby protecting the surrounding tissue. In oneembodiment, the covering can include an inflow strip member and anoutflow strip member secured to the cushioning layer and folded over theapices of the strut members to form the inflow and outflow protectiveportions.

Embodiments of the disclosed technology can be used in combination withvarious prosthetic heart valves configured for implantation at variouslocations within the heart. A representative, non-limiting example is aprosthetic heart valve for replacing the function of the native mitralvalve. FIGS. 1 and 2 illustrate the mitral valve of the human heart. Themitral valve controls the flow of blood between the left atrium and theleft ventricle. After the left atrium receives oxygenated blood from thelungs via the pulmonary veins, the mitral valve permits the flow of theoxygenated blood from the left atrium into the left ventricle. When theleft ventricle contracts, the oxygenated blood that was held in the leftventricle is delivered through the aortic valve and the aorta to therest of the body. Meanwhile, the mitral valve closes during ventricularcontraction to prevent any blood from flowing back into the left atrium.

When the left ventricle contracts, the blood pressure in the leftventricle increases substantially, which urges the mitral valve closed.Due to the large pressure differential between the left ventricle andthe left atrium during this time, a possibility of prolapse, or eversionof the leaflets of the mitral valve back into the atrium, arises. Aseries of chordae tendineae therefore connect the leaflets of the mitralvalve to papillary muscles located on the walls of the left ventricle,where both the chordae tendineae and the papillary muscles are tensionedduring ventricular contraction to hold the leaflets in the closedposition and to prevent them from extending back towards the leftatrium. This generally prevents backflow of oxygenated blood back intothe left atrium. The chordae tendineae are schematically illustrated inboth the heart cross-section of FIG. 1 and the top view of the mitralvalve of FIG. 2.

A general shape of the mitral valve and its leaflets as viewed from theleft atrium is shown in FIG. 2. Various complications of the mitralvalve can potentially cause fatal heart failure. One form of valvularheart disease is mitral valve leak or mitral regurgitation,characterized by abnormal leaking of blood from the left ventriclethrough the mitral valve back into the left atrium. This can be causedby, for example, dilation of the left ventricle, which can causeincomplete coaptation of the native mitral leaflets resulting in leakagethrough the valve. Mitral valve regurgitation can also be caused bydamage to the native leaflets. In these circumstances, it may bedesirable to repair the mitral valve, or to replace the functionality ofthe mitral valve with that of a prosthetic heart valve, such as atranscatheter heart valve.

Some transcatheter heart valves are designed to be radially crimped orcompressed to facilitate endovascular delivery to an implant site at apatient's heart. Once positioned at a native valve annulus, thereplacement valve is then expanded to an operational state, for example,by an expansion balloon, such that a leaflet structure of the prostheticheart valve regulates blood flow through the native valve annulus. Inother cases, the prosthetic valve can be mechanically expanded orradially self-expand from a compressed delivery state to the operationalstate under its own resiliency when released from a delivery sheath. Oneembodiment of a prosthetic heart valve is illustrated in FIG. 3. Atranscatheter heart valve with a valve profile similar to the prostheticvalve shown in FIG. 3 is the Edwards Lifesciences SAPIEN XT™ valve. Theprosthetic valve 1 in FIG. 3 has an inflow end 2 and an outflow end 3,includes a frame or stent 10, and a leaflet structure 20 supportedinside the frame 10. In some embodiments, a skirt 30 is attached to aninner surface of the frame 10 to form a more suitable attachment surfacefor the valve leaflets of the leaflet structure 20.

The frame 10 can be made of any body-compatible expandable material thatpermits both crimping to a radially collapsed state and expansion backto the expanded functional state illustrated in FIG. 3. For example, inembodiments where the prosthetic valve is a self-expandable prostheticvalve that expands to its functional size under its own resiliency, theframe 10 can be made of Nitinol or another self-expanding material. Insome embodiments, the prosthetic valve can be a plastically expandablevalve that is expanded to its functional size by a balloon or anotherexpansion device, in which case the frame can be made of a plasticallyexpandable material, such as stainless steel or a cobalt chromium alloy.Other suitable materials or combinations of materials can also be used.

The frame 10 can comprise an annular structure having a plurality ofvertically extending commissure attachment posts 11, which attach andhelp shape the leaflet structure 20 therein. Additional vertical postsor strut members 12, along with circumferentially extending strutmembers 13, help form the rest of the frame 10. The strut members 13 ofthe frame 10 zig-zag and form edged crown portions or apices 14 at theinflow and outflow ends 2, 3 of the valve 1. Furthermore, the attachmentposts 11 can also form edges at one or both ends of the frame 10.

In prosthetic valve 1, the skirt 30 can be attached to an inner surfaceof the valve frame 10 via one or more threads 40, which generally wraparound to the outside of various struts 11, 12, 13 of the frame 10, asneeded. The skirt 30 provides a more substantive attachment surface forportions of the leaflet structure 20 positioned closer to the inflow end2 of the valve 1.

FIGS. 4A and 4B show side cross-sectional views of embodiments ofdifferent anchors that can be used to facilitate implantation of thevalve 1 at a native valve, such as at the mitral valve position ortricuspid valve position of a an animal or patient. As shown, forexample, in FIGS. 4A and 4B, a left side of a heart 80 includes a leftatrium 82, a left ventricle 84, and a mitral valve 86 connecting theleft atrium 82 and the left ventricle 84. The mitral valve 86 includesanterior and posterior leaflets 88 that are connected to an inner wallof the left ventricle 84 via chordae tendineae 90 and papillary muscles92.

In FIG. 4A, a first anchoring device includes a flexible ring or halo 60that surrounds the native leaflets 88 of the native valve 86 and/or thechordae tendineae 90. The ring 60 pinches or urges portions of theleaflets inwards, in order to form a more circular opening at the nativevalve, for more effective implantation of the prosthetic valve 1. Thevalve prosthesis 1 is retained at the native valve 86 by the ring anchor60 (which acts as a docking device), and can be delivered to theposition shown, for example, by positioning the valve 1 in the nativevalve 86 while the prosthetic valve 1 is delivered and expanded once itis positioned as shown in FIG. 4A. Once expanded, the prosthetic valve 1pushes outwardly against the ring anchor 60 to secure the positions ofboth the valve 1 and the ring anchor 60. In some embodiments, anundersized ring anchor 60 with an inner diameter that is slightlysmaller than the diameter of the prosthetic valve 1 in its expandedstate can be used, to provide stronger friction between the parts,leading to more secure attachment. As can be seen in FIG. 4A, at least aportion of the native valve leaflets 88 and/or a portion of the chordaetendineae 90 are pinched or sandwiched between the valve 1 and the ringanchor 60 to secure the components to the native anatomy.

FIG. 4B is similar to FIG. 4A, except instead of a ring anchor 60, ahelical or coiled anchor or docking device 70 is utilized instead. Thehelical anchor 70 can include more coils or turns than the ring anchor60, and can extend both upstream and downstream of the native valve 86.The helical anchor 70 in some situations can provide a greater and moresecure attachment area against which the prosthetic valve 1 can abut.Similar to the ring anchor 60 in FIG. 4A, at least a portion of thenative valve leaflets 88 and/or the chordae 90 are pinched between thevalve 1 and the helical anchor 70. Methods and devices for implantinganchors/docking devices and prosthetic valves, which can be used withthe inventions in this disclosure, are described in U.S. applicationSer. No. 15/682,287, filed on Aug. 21, 2017 and published as US2018/0055628, U.S. application Ser. No. 15/684,836, filed on Aug. 23,2017 and published as US 2018/0055630, and U.S. application Ser. No.15/984,661, filed on May 21, 2018 and published as US 2018/0318079,which are each incorporated herein by reference.

FIG. 4C illustrates another representative embodiment of an anchor ordocking device 300 that can be used in combination with any of theprosthetic valves described herein. The anchor 300 has a functionalcoil/turn region or central region 302 and an encircling turn or lowerregion 304. The anchor 300 can also, optionally, have an upper region306. The lower region 304 includes one or more turns that can beconfigured to encircle or capture the chordae tendineae and/or theleaflets of a native valve, such as the mitral valve or tricuspid valve.The central region 302 includes a plurality of turns configured toretain the prosthetic valve at the native valve. The upper region 306can include one or more turns, and can be configured to keep the anchorfrom being dislodged from the valve annulus prior to implantation of theprosthetic valve. In some embodiments, the upper region 306 can bepositioned over the floor of the atrium, and can be configured to keepthe turns of the central region 302 positioned high within the nativevalve apparatus.

The anchor 300 can, optionally, also include an extension portion 308positioned between the central region 302 and the upper region 306. Insome embodiments, the extension portion 308 can instead be positioned,for example, wholly in the central region 302 (e.g., at an upper portionof the central region) or wholly in the upper region 306. The extensionportion 308 includes a part of the coil that extends substantiallyparallel to a central axis of the anchor. In some embodiments, theextension portion 308 can be angled relative to the central axis of theanchor. In some embodiments, the extension portions 308 can be longer orshorter than that shown and can have a larger or smaller angle relativeto region 302 and/or region 306. The extension portion 308 can serve tospace the central region 302 and the upper region 306 apart from oneanother in a direction along the central axis so that a gap is formedbetween the atrial side and the ventricular side of the anchor.

The extension portion 308 of the anchor can be configured to bepositioned through, near, and/or around the native valve annulus, inorder to reduce the amount of the anchor that passes through, pushes, orrests against the native annulus and/or the native leaflets when theanchor is implanted. This can reduce the force applied by the anchor onthe native valve and reduce abrasion of the native leaflets. In onearrangement, the extension portion 308 is positioned at and passesthrough one of the commissures of the native valve. In this manner, theextension portion 308 can space the upper region 306 apart from thenative leaflets of the native valve to prevent the upper region 306 frominteracting with the native leaflets from the atrial side. The extensionportion 308 also elevates the upper region 306 such that the upperregion contacts the atrial wall above the native valve, which can reducethe stress on and around the native valve, as well as provide for betterretention of the anchor.

As shown in FIG. 4C, the anchor 300 can further include one or moreopenings configured as through holes 310 at or near one or both of theproximal and distal ends of the anchor. The through holes 310 can serve,for example, as suturing holes for attaching a cover layer over the coilof the anchor, and/or as an attachment site or tethering holes fordelivery tools such as a pull wire, retention member, retention suture,etc. In some embodiments, a width or thickness of the coil of the anchor300 can also be varied along the length of the anchor. For example, acentral portion of the anchor and/or extension 308 can be made thinnerthan end portions of the anchor. This can allow the central portionand/or extension 308 to exhibit greater flexibility, while the endportions can be stronger or more robust. In certain examples, making theend portions of the coil relatively thicker can also provide moresurface area for suturing or otherwise attaching a cover layer to thecoil of the anchor.

In certain embodiments, the anchor or docking device 300 can beconfigured for insertion through the native valve annulus in acounter-clockwise direction. For example, the anchor can be advancedthrough commissure A3P3, commissure A1P1, or through another part of thenative mitral valve. The counter-clockwise direction of the coil of theanchor 300 can also allow for bending of the distal end of the deliverycatheter in a similar counter-clockwise direction, which can be easierto achieve than to bend the delivery catheter in the clockwisedirection. However, it should be understood that the anchor can beconfigured for either clockwise or counter-clockwise insertion throughthe valve, as desired.

Returning to the prosthetic valve example of FIG. 3, the prostheticvalve 1 generally includes a metal frame 10 that forms a number ofedges. In addition, many frames 10 are constructed with edged crowns orapices 14 and protruding commissure attachment posts 11, as well asthreads 40 that can be exposed along an outer surface of the frame 10.These features can cause damage to the native tissue, such as tissuelodged between the prosthetic valve 1 and the anchor 60, 70, forexample, by movement or friction between the native tissue and thevarious abrasive surfaces of the prosthetic valve 1. In addition, othernative tissue in close proximity to the prosthetic valve 1, such as thechordae tendineae, can also potentially be damaged.

FIGS. 5-7 illustrate a representative embodiment of a prosthetic heartvalve 100 similar to the Edwards Lifesciences SAPIEN™ 3 valve, which isdescribed in detail in U.S. Pat. No. 9,393,110, which is incorporatedherein by reference. The prosthetic valve 100 includes a frame 102formed by a plurality of angled strut members 104, and having an inflowend 106 and an outflow end 108. The prosthetic valve 100 also includes aleaflet structure comprising three leaflets 110 situated at leastpartially within the frame 102 and configured to collapse in a tricuspidarrangement similar to the aortic valve, although the prosthetic valvecan also include two leaflets configured to collapse in a bicuspidarrangement in the manner of the mitral valve, or more than threeleaflets, as desired. The strut members 104 can form a plurality ofapices 124 arranged around the inflow and outflow ends of the frame.

The prosthetic heart valve can include a covering or outer covering 112configured to cushion (protect) native tissue in contact with theprosthetic valve after implantation, and to reduce damage to the tissuedue to movement or friction between the tissue and surfaces of thevalve. The covering 112 can also reduce paravalvular leakage. In theembodiment of FIG. 5, the covering 112 includes a first layer configuredas a backing layer 114 (see, e.g., FIG. 8), and a second layerconfigured as a cushioning layer 116. The cushioning layer 116 can bedisposed on the backing layer 114, and can comprise a soft, plushsurface 118 oriented radially outward so as to protect tissue or objectsin contact with the cushioning layer. In the illustrated configuration,the covering 112 also includes an atraumatic inflow protective portion120 extending circumferentially around the inflow end 106 of the frame,and an atraumatic outflow protective portion 122 extendingcircumferentially around the outflow end 108 of the frame. The portionof the cushioning layer 116 between the inflow and outflow protectiveportions 120, 122 can define a main cushioning portion 136. The firstlayer 114 and the second layer 116 can together form a sealing member orcover member that can be placed around the frame to form the covering112. The sealing member/cover member can also comprise the protectiveportions 120, 122.

FIG. 8 is a cross-sectional view schematically illustrating theprosthetic valve 100 with the leaflet structure removed for purposes ofillustration. The covering 112 extends around the exterior of the frame102, such that an interior surface of the backing layer 114 is adjacentor against the exterior surfaces of the strut members 104. Asillustrated in FIG. 8, the cushioning layer 116 can have a length thatis greater than the length of the frame as measured along a longitudinalaxis 126 of the frame. Thus, the covering 112 can be situated such thatthe cushioning layer 116 extends distally (e.g., in the upstreamdirection) beyond the apices 124 of the strut members at the inflow end106 of the frame, with the portion of the cushioning layer extendingbeyond the apices being referred to herein as distal end portion 128. Atthe opposite end of the valve, the cushioning layer 116 can extendproximally (e.g., in the downstream direction) beyond the apices 124 ofthe strut members, with the portion located beyond the apices beingreferred to as proximal end portion 130. The distances by which theproximal and distal end portions 128, 130 of the cushioning layer 116extend beyond the apices at the respective end of the valve can be thesame or different depending upon, for example, the dimensions of thevalve, the particular application, etc.

The backing layer 114 can have sufficient length in the axial directionsuch that a proximal end portion or flap 132 of the backing layer 114can be folded over the proximal end portion 130 of the cushioning layer116 in the manner of a cuff to form the outflow protective portion 122.Meanwhile, a distal end portion or flap 134 of the backing layer 114 canbe folded over the distal end portion 128 of the cushioning layer 116 toform the inflow protective portion 120. The proximal and distal flaps132, 134 of the backing layer 116 can be secured to the underlyingsection of the backing layer by attachment means, for example, sutures136, adhesive, clips, etc. In this manner, the inflow and outflowprotective portions 120, 122 are constructed such that the proximal anddistal end portions 130, 128 of the cushioning layer 116 are at leastpartially enclosed by the flaps 132, 134 of the backing layer 116. Thisconstruction provides sufficient strength and resistance to bending tothe inflow and outflow protective portions 120, 122 so that they extendalong the longitudinal axis 126 of the valve without bending orotherwise protruding into the inner diameter of the valve (e.g., bybending under their own weight, by blood flow, or by blood pressure). Inthis manner, the inflow and outflow protective portions 120, 122minimally impact flow through the prosthetic valve and avoid interferingwith the prosthetic valve leaflets, reducing flow disturbances, andpotentially reducing the risk of thrombus.

In the illustrated configuration, the inflow protective portion 120 canextend beyond the apices 124 of the strut members at the inflow end ofthe frame by a distance d₁, and the outflow protective portion 122 canextend beyond the apices 124 of the strut members at the outflow end ofthe frame by a distance d₂. The distances d₁ and d₂ can be the same ordifferent, depending upon the type of prosthetic valve, the treatmentlocation, etc. For example, for a 29 mm prosthetic valve, the distancesd₁ and d₂ can be from about 0.5 mm to about 3 mm. In a representativeembodiment, the distances d₁ and d₂ can be from about 1 mm to about 2mm. Because the inflow and outflow protective portions 120, 122 extendbeyond the apices 124 of the respective ends of the frame, the inflowand outflow protective portions can shield adjacent tissue and/oranother implant adjacent the prosthetic valve from contacting the apices124 of the frame.

For example, FIG. 10 illustrates the prosthetic valve 100 implantedwithin an anchor or docking device 70 in the native valve 86, similar toFIGS. 4A and 4B above. In the illustrated example, the inflow endportion of the prosthetic valve is shown positioned above the superiorsurface of the native valve annulus and spaced from surrounding tissue.However, in other implementations, depending on the axial positioning ofthe prosthetic valve, which can be varied, the inflow protective portion120 can contact the native leaflets 88 and prevent them from directlycontacting the apices 124 at the inflow end of the frame. Depending onthe diameter of the prosthetic valve at the inflow end, the inflowprotective portion 120 can serve to prevent the atrium wall fromdirectly contacting the apices 124 at the inflow end of the frame.

As shown in FIG. 10, the anchor 70 can also rest against the compliantinflow protective portion 120. Meanwhile, the portions of the nativeleaflets 88 captured between the anchor 70 and the prosthetic valve 100can be cushioned by the plush surface 118 of the main cushioning portion136. In certain embodiments, the soft, compliant nature and texture ofthe cushioning layer 116 can increase friction between the nativeleaflets and the prosthetic valve. This can reduce relative movement ofthe native leaflets and the prosthetic valve as the left ventricleexpands and contracts, reducing the likelihood of damage to the nativeleaflets and the surrounding tissue. The cushioning layer 116 can alsoprovide increased retention forces between the anchor 70 and theprosthetic valve 100. The plush, compressible nature of the cushioninglayer 116 can also reduce penetration of the covering 112 through theopenings in the frame 102 caused by application of pressure to thecovering, thereby reducing interference with the hemodynamics of thevalve. Additionally, the outflow cushioning portion 122 can protect thechordae tendineae 90 from contacting the strut members of the frame, andin particular the apices 124 at the outflow end of the frame, therebyreducing the risk of injury or rupture of the chordae.

The backing layer 114 can comprise, for example, any of various wovenfabrics, such as gauze, polyethylene terephthalate (PET) fabric (e.g.,Dacron), polyester fabric, polyamide fabric, or any of various non-wovenfabrics, such as felt. In certain embodiments, the backing layer 114 canalso comprise a film including any of a variety of crystalline orsemi-crystalline polymeric materials, such as polytetrafluorethylene(PTFE), PET, polypropylene, polyamide, polyetheretherketone (PEEK), etc.In this manner, the backing layer 114 can be relatively thin and yetstrong enough to allow the covering 112 to be sutured to the frame, andto allow the prosthetic valve to be crimped, without tearing.

As stated above, the cushioning layer 116 can comprise at least onesoft, plush surface 118. In certain examples, the cushioning layer 116can be made from any of a variety of woven or knitted fabrics whereinthe surface 116 is the surface of a plush nap or pile of the fabric.Exemplary fabrics having a pile include velour, velvet, velveteen,corduroy, terrycloth, fleece, etc. FIG. 9 illustrates a representativeembodiment of the cushioning layer 116 in greater detail. In theembodiment of FIG. 9, the cushioning layer 116 can have a base layer 162(a first layer) from which the pile 158 (a second layer) extends. Thebase layer 162 can comprise warp and weft strands (e.g., yarns, etc.)woven or knitted into a mesh-like structure. For example, in arepresentative configuration, the strands/yarns of the base layer 162can be flat strands/yarns with a denier range of from about 7 dtex toabout 100 dtex, and can be knitted with a density of from about 20 toabout 100 wales per inch and from about 30 to about 110 courses perinch. The strands/yarns can be made from, for example, biocompatiblethermoplastic polymers such as PET, Nylon, ePTFE, etc., other suitablenatural or synthetic fibers, or soft monolithic materials.

The pile 158 can comprise pile strands or pile yarns 164 woven orknitted into loops. In certain configurations, the pile strands or pileyarns 164 can be the warp strands/yarns or the weft strands/yarns of thebase layer 162 woven or knitted to form the loops. The pile strands orpile yarns 164 can also be separate strands/yarns incorporated into thebase layer, depending upon the particular characteristics desired. Incertain embodiments, the loops can be cut such that the pile 158 is acut pile in the manner of, for example, a velour fabric. FIGS. 5-8illustrate a representative embodiment of the cushioning layer 116configured as a velour fabric. In some embodiments, the loops can beleft intact to form a looped pile in the manner of, for example,terrycloth. FIG. 9 illustrates a representative embodiment of thecushioning layer 116 in which the pile strands or pile yarns 164 areknitted to form loops 166. FIG. 11 illustrates an embodiment of thecovering 112 incorporating the cushioning layer 116 of FIG. 9.

In some configurations, the pile strands or pile yarns 164 are texturedstrands/yarns having an increased surface area due to, for example, awavy or undulating structure. In configurations such as the looped pileembodiment of FIG. 11, the loop structure and the increased surface areaprovided by the textured strands or textured yarn of the loops 166 canallow the loops to act as a scaffold for tissue growth into and aroundthe loops of the pile. Promoting tissue growth into the pile 158 canincrease retention of the valve at the implant site and contribute tolong-term stability of the valve.

The cushioning layer embodiments described herein can also contribute toimproved compressibility and shape memory properties of the covering 112over known valve coverings and skirts. For example, the pile 158 can becompliant such that it compresses under load (e.g., when in contact withtissue, implants, or the like), and returns to its original size andshape when the load is relieved. This can help to improve sealingbetween the cushioning layer 116 and, for example, support structures orother devices such as the helical anchor 70 in which the prostheticvalve is deployed, or between the cushioning layer and the walls of thenative annulus. The compressibility provided by the pile 158 of thecushioning layer 116 is also beneficial in reducing the crimp profile ofthe prosthetic valve. Additionally, the covering 112 can prevent theleaflets 110 or portions thereof from extending through spaces betweenthe strut members 104 as the prosthetic valve is crimped, therebyreducing damage to the prosthetic leaflets due to pinching of theleaflets between struts.

In some embodiments, the cushioning layer 116 is made of non-wovenfabric such as felt, or fibers such as non-woven cotton fibers. Thecushioning layer 116 can also be made of porous or spongey materialssuch as, for example, any of a variety of compliant polymeric foammaterials, or woven or knitted fabrics, such as woven or knitted PET. Insome embodiments, the proximal and distal end portions of the cushioninglayer 116 of the embodiment of FIG. 11 are free of loops 166, and theinflow and outflow protective portions 120, 122 are formed by foldingthe base layer 162 back on itself to form cuffs at the inflow andoutflow ends of the valve.

In a representative example illustrated in FIG. 12, the covering 112 ofFIGS. 5-8 is made, at least in part, by cutting a fabric material (e.g.,a PET fabric) with a stencil 138 to form the backing layer 114. In theillustrated embodiment, the stencil 138 is shaped like a parallelogram,although other configurations and shapes are possible. The angles of thecorners of the stencil 138 can be shaped such that the fabric materialis cut at about a 45 degree angle relative to the direction of thefibers of the fabric. This can improve the crimpability of the resultingbacking layer 114 by, for example, allowing the backing layer to stretchalong a direction diagonal to the warp and weft strands/yarns. FIG. 18illustrates a plan view of a representative example of the backing layer114 after being cut using the parallelogram stencil 138.

The cushioning layer 116 can be attached (e.g., by sutures, adhesive,etc.) to the backing layer 114. In FIG. 12, the location of the proximaland distal ends of the frame 102 when the covering is attached to theframe are represented as dashed lines 140, 141 on the backing layer 114.Meanwhile, dashed lines 142, 144 represent the location of the proximaland distal edges of the cushioning layer 116 once the cushioning layeris secured to the backing layer. For example, the cushioning layer 116can be sutured to the backing layer 114 along the proximal and distaledges at or near lines 142, 144. As shown in FIG. 12, line 142representing the proximal edge of the cushioning layer 116 can be offsetfrom the proximal edge 146 of the backing layer 114 by a distance d₃ tocreate the proximal flap 132. Meanwhile, line 144 representing thedistal edge of the cushioning layer 116 can be offset from the distaledge 148 of the backing layer 114 by a distance d₄ to create the distalflap 134. The distances d₃ and d₄ can be the same or different, asdesired. For example, depending upon the size of the valve and the sizeof the inflow and outflow cushioning portions, the distances d₃ and d₄can be, for example, about 3-5 mm. In some embodiments, the distances d₃and d₄ can be about 3.5 mm.

Once the cushioning layer 116 is secured to the backing layer 114, theresulting swatch can be folded and sutured into a cylindrical shape. Theflaps 132, 134 of the backing layer 114 can be folded over the edges ofthe cushioning layer 116 and sutured to form the inflow and outflowprotective portions 120, 122. The resulting covering 112 can then besecured to the frame 102 by attachment means, for example, suturing,clipping, adhering, etc. it to the strut members 104.

FIGS. 13 and 14 illustrate an example of the covering 112 in which theinflow and outflow protective portions 120, 122 are formed with separatepieces of material that wrap around the ends of the cushioning layer 116at the inflow and outflow ends of the valve. For example, the proximalend portion 130 of the cushioning layer 116 can be covered by a memberconfigured as a strip 150 of material that wraps around the cushioninglayer from the interior surface 170 (e.g., the surface adjacent theframe) of the cushioning layer 116, over the circumferential edge of theproximal end portion 130, and onto the exterior surface 118 of thecushioning layer to form the outflow protective portion 122. Likewise, amaterial strip member 152 can extend from the interior surface 170 ofthe cushioning layer, over the circumferential edge of the distal endportion 128, and onto the exterior surface of the cushioning layer toform the inflow protective portion 120. The strip members 150, 152 canbe sutured to the cushioning layer 116 along the proximal and distaledge portions 130, 128 of the cushioning layer at suture lines 154, 156,respectively.

In certain configurations, the strip members 150, 152 can be made fromany of various natural materials and/or tissues, such as pericardialtissue (e.g., bovine pericardial tissue). The strip members 150, 152 canalso be made of any of various synthetic materials, such as PET and/orexpanded polytetrafluoroethylene (ePTFE). In some configurations, makingthe strip members 150, 152 from natural tissues such as pericardialtissue can provide desirable properties such as strength, durability,fatigue resistance, and compliance, and cushioning and reduced frictionwith materials or tissues surrounding the implant.

FIG. 15 illustrates a prosthetic valve 200 including an example of anouter cover or covering 202 comprising a cushioning layer 204 made of aspacer fabric. In the illustrated embodiment, the outer covering 202 isshown without inflow and outflow protective portions, and with thecushioning layer 204 extending along the full length of the frame fromthe inflow end to the outflow end of the valve. However, the outercovering 202 may also include inflow and/or outflow protective portions,as described elsewhere herein. The cushioning layer 204 can be or form asealing member or cover member, which can be attached to the frame toform the covering 202.

Referring to FIGS. 16 and 17, the spacer fabric cushioning layer orsealing member/cover member can comprise a first layer 206, a secondlayer 208, and a spacer layer 210 extending between the first and secondlayers to create a three-dimensional fabric. The first and second layers206, 208 can be woven fabric or mesh layers. In certain configurations,one or more of the first and second layers 206, 208 can be woven suchthat they define a plurality of openings 212. In some examples, openingssuch as the openings 212 can promote tissue growth into the covering202. In some embodiments, the layers 206, 208 need not define openings,but can be porous, as desired.

The spacer layer 210 can comprise a plurality of pile strands or pileyarns 214. The pile strands or pile yarns 214 can be, for example,monofilament strands/yarns arranged to form a scaffold-like structurebetween the first and second layers 206, 208. For example, FIGS. 16 and17 illustrate an embodiment in which the pile strands or pile yarns 214extend between the first and second layers 206, 208 in a sinusoidal orlooping pattern.

In certain examples, the pile strands or pile yarns 214 can have arigidity that is greater than the rigidity of the fabric of the firstand second layers 206, 208 such that the pile strands or pile yarns 214can extend between the first and second layers 206, 208 withoutcollapsing under the weight of the second layer 208. The pile strands orpile yarns 214 can also be sufficiently resilient such that the pilestrands or pile yarns can bend or give when subjected to a load,allowing the fabric to compress, and return to their non-deflected statewhen the load is removed.

The spacer fabric can be warp-knitted, or weft-knitted, as desired. Someconfigurations of the spacer cloth can be made on a double-bar knittingmachine. In a representative example, the strands/yarns of the first andsecond layers 206, 208 can have a denier range of from about 10 dtex toabout 70 dtex, and the strands/yarns of the monofilament pilestrands/yarns 214 can have a denier range of from about 2 mil to about10 mil. The pile strands or pile yarns 214 can have a knitting densityof from about 20 to about 100 wales per inch, and from about 30 to about110 courses per inch. Additionally, in some configurations (e.g.,warp-knitted spacer fabrics) materials with different flexibilityproperties may be incorporated into the spacer cloth to improve theoverall flexibility of the spacer cloth.

FIGS. 19-21 illustrate an example of a prosthetic heart valve 400including an outer covering with inflow and outflow protective portionsthat encapsulate the apices of the strut members. For example, theprosthetic valve can include a frame 402 formed by a plurality of strutmembers 404 defining apices 420 (FIGS. 22 and 24), and can have aninflow end 406 and an outflow end 408. A plurality of leaflets 410 canbe situated at least partially within the frame 402.

The prosthetic valve can include a covering or outer covering 412situated about the frame 402. The outer covering 412 can include a mainlayer or main cushioning layer 414 including a plush exterior surface432 (e.g., a first surface), similar to the cushioning layer 116 of FIG.13 above. The covering 412 can also include an inflow protective portion416 extending circumferentially around the inflow end 406 of the valve,and an outflow protective portion 418 extending circumferentially aroundthe outflow end 408 of the valve. The inflow and outflow protectiveportions 416, 418 can be formed with separate pieces of material thatare folded around the circumferential ends of the cushioning layer 414at the inflow and outflow ends of the valve such that the protectiveportions encapsulate the apices 420 of the strut members. The layer 414alone or together with protective portions 416, 418 can form a sealingmember or cover member that can be placed around the frame to form thecovering 412.

For example, with reference to FIG. 22, the inflow protective portion416 can comprise a member configured as a strip 424 of materialincluding a first circumferential edge portion 426 and a secondcircumferential edge portion 428. The strip member 424 of material canbe folded such that the first circumferential edge portion 426 isadjacent (e.g., contacting) an inner skirt 430 disposed within the frame402. The first circumferential edge portion 426 thereby forms a first orinner layer of the inflow protective portion 416. The strip member 424can extend over the apices 420 of the strut members, and over an inflowend portion 422 of the cushioning layer 414 such that the secondcircumferential edge portion 428 is disposed on the exterior surface 432of the cushioning layer 414. In this manner, the inflow end portion 422of the cushioning layer 414 can form a second layer of the inflowprotective portion 414, and the second circumferential edge portion 428can form a third or outer layer of the inflow protective portion. Thefirst and second circumferential edge portions 426, 428 of the stripmember 424 can be secured to the strut members 404 (e.g., the rung ofstruts nearest the inflow end 406) with attachment means, such assutures 434, 435, adhesive, etc. Thus, the strip member 424 canencapsulate the apices 420, along with the inflow end portion 422 of thecushioning layer 414, between the first and second circumferential edgeportions 426, 428.

In the illustrated configuration, the inflow protective portion 416extends beyond the apices 420 of the frame, similar to the embodimentsabove. In particular, the inflow end portion 422 of the cushioning layer414 can extend beyond the apices 420 of the frame and into the inflowprotective portion 416 within the folded strip 424. In this manner, theinflow end portion 422 of the cushioning layer 414, together with thestrip member 424, can impart a resilient, cushioning quality to theinflow protective portion 416. This can also allow the inflow protectiveportion 416 to resiliently deform to accommodate and protect, forexample, native tissue, other implants, etc., that come in contact withthe inflow protective portion.

Optionally, one or more additional materials or layers can be includedunder and/or to form any of the protective portions (e.g., 120, 122,416, 418, 518, 520, etc.) to provide added cushioning and/or protectionat the apices of the frame.

In the illustrated embodiment, the inflow end portion 422 can extendbeyond the apices 420 by a distance d₁. The distance d₁ can beconfigured such the inflow end portion 422 can extend over or cover theapices 420 when the inflow protective portion 416 comes in contact with,for example, native tissue at the treatment site. The strip member 424can also form a dome over the edge of the of the inflow end portion 422such that the edge of the inflow end portion 422 is spaced apart fromthe domed portion of the strip member 424. In some embodiments, thestrip member 424 is folded such that it contacts the edge of the inflowedge portion 422, similar to the embodiment of FIG. 13.

The outflow protective portion 418 can include a member configured as astrip 436 of material folded such that a first circumferential edgeportion 438 is adjacent (e.g., contacting) inner surfaces 440 of thestrut members, and a second circumferential edge portion 442 is disposedon the exterior surface 432 of the cushioning layer 414, similar to theinflow protective portion 416. An outflow end portion 444 of thecushioning layer 414 can extend beyond the apices 420 by a distance d₂,and can be encapsulated by the strip member 436 together with the apices420 between the first and second circumferential edge portions 438, 442.The distance d₂ can be the same as distance d₁ or different, as desired.The strip member 436 can be secured to the strut members 404 withattachment means, such as sutures 446, 447, adhesive, etc. The stripmember 436 can also form a domed shape similar to the strip member 424.

In certain configurations, the cushioning layer 414 can be a fabricincluding a plush pile, such as a velour fabric, or any other type ofplush knitted, woven, or non-woven material, as described above. In someembodiments, the cushioning layer 414 may also comprise a relatively lowthickness woven fabric without a plush pile. In certain configurations,the strip members 424, 436 can be made of resilient natural tissuematerials such as pericardium. Optionally, the strip members can also bemade from fabric or polymeric materials such as PTFE or ePTFE.

FIGS. 23-26 illustrate a representative method of making the covering orouter covering 412 and attaching the covering to the prosthetic valve400 to form the inflow and outflow protective portions 416, 418. FIG. 23illustrates the outer covering 412 in an unfolded configuration prior tosecuring the covering to the frame 402. As illustrated in FIG. 23, thesecond circumferential edge portion 428 of the strip member 424 can besutured to the plush surface 432 (e.g., the first surface) of thecushioning layer 414 at the inflow end portion 422 of the cushioninglayer. The second circumferential edge portion 442 of the strip member436 can be sutured to the plush surface 432 of the cushioning layer 414at the outflow end portion 444 of the cushioning layer.

In the illustrated configuration, the cushioning layer 414 and the stripmembers 424, 436 can have a length dimension L corresponding to acircumference of the frame 402. In a representative example, the lengthdimension L can be about 93 mm. The strip members 424, 436 can also haverespective width dimensions W₁, W₂. Referring to width dimension W₁ forpurposes of illustration, the width dimension W₁ can be configured suchthat the strip member 424 extends from the interior of the valve to theexterior of the valve without contacting the apices 420 of the strutmembers, as shown in FIG. 22. For example, the width dimension W₁ can beconfigured such that the strip member 424 extends from adjacent the rungof strut members 404 at the inflow end 406 of the frame to the exteriorof the valve adjacent the same rung of strut members and forms a domedshape over the apices 420. In certain configurations, the widthdimension W₁ can be about 6 mm. The width dimension W₂ can be the sameas W₁ or different, as desired.

Referring to FIG. 24, the outer covering 412 can be folded and suturedinto a cylindrical shape. The outer covering 412 can then be situatedaround the frame 402 such that a second or interior surface 454 of thecushioning layer 414 is oriented toward the frame. In certainconfigurations, the frame 402 can already include the inner skirt 430and the leaflet structure 410, as shown in FIG. 24.

Referring to FIGS. 25 and 26, the outer covering 412 can then be suturedto the frame. For example, as illustrated in FIG. 25, the strip member424 can be aligned with an adjacent rung of strut members 404 (e.g., therung of strut members nearest the inflow end of the frame). Thecushioning layer 414 and/or the strip member 424 can then be sutured tothe strut members 404 at suture line 434. The strip member 424 can thenbe folded over the apices 420 at the inflow end of the frame, and thefirst and second circumferential edge portions 426, 428 can be suturedto each other at suture line 435 to form the inflow protective portion416. In some embodiments, the strip member 424 is folded and sutured toform the inflow protective portion 416 before the outer covering 412 issutured to the frame.

The outflow protective portion 418 can be formed in a similar manner.For example, the strip member 426 can be aligned with the rung of strutmembers 404 adjacent the outflow end 408 of the frame, and the stripmember 426 and/or the cushioning layer 414 can be sutured to the strutmembers. The strip member 436 can then be folded over the apices 420 andthe cushioning layer 414 at the outflow end of the frame, and the firstand second circumferential edge portions 438, 442 can be suturedtogether, and to the rung of strut members 404 adjacent the outflow endof the frame, to form the outflow protective portion 418. The covering412 can also be sutured to the frame at one or more additionallocations, such as at suture lines 448 and 450, as shown in FIG. 22.

FIGS. 27 and 28 illustrates an example of a prosthetic heart valve 500including a frame 502 formed by a plurality of strut members 504defining apices 506 (FIG. 28), similar to the frame 102 described aboveand in U.S. Pat. No. 9,393,110. The prosthetic valve 500 can have aninflow end 508 and an outflow end 510, and can include a leafletstructure (not shown) situated at least partially within the frame.

The prosthetic valve can include an outer covering 514 situated aboutthe frame 502. The covering or outer covering 514 can include a maincushioning layer 516 (also referred to as a main layer) having acylindrical shape, and made from a woven, knitted, or braided fabric(e.g., a PET fabric, an ultra-high molecular weight polyethylene(UHMWPE) fabric, a PTFE fabric, etc.). In some embodiments, the fabricof the main cushioning layer 516 can include a plush pile. In someembodiments, the fabric of the main cushioning layer 516 can comprisetexturized strands (e.g., texturized yarns, etc.) in which theconstituent fibers of the strands/yarns have been bulked by, forexample, being twisted, heat set, and untwisted such that the fibersretain their deformed, twisted shape and create a voluminous fabric. Thevolume contributed by the texturized strands/yarns can improve thecushioning properties of the covering, as well as increase frictionbetween the fabric and the surrounding anatomy and/or an anchoringdevice into which the valve is deployed. The layer 516 alone or togetherwith protective portions 518, 520 and/or layers 530, 534 can form asealing member or cover member that can be placed around the frame toform the covering 514.

The outer covering 514 can include an inflow protective portion 518extending circumferentially around the inflow end 508 of the frame, andan outflow protective portion 520 extending circumferentially around theoutflow end 510 of the frame. In certain embodiments, the inflow andoutflow protective portions 518 and 520 can be formed on the fabric ofthe main cushioning layer 516 such that the outer covering 514 is aone-piece, unitary construction, as described further below.

Referring to FIG. 28, the main cushioning layer 516 can include a firstcircumferential edge portion 522 (also referred to as an inflow edgeportion) located adjacent the inflow end 508 of the valve, which canform a part of the inflow protective portion 518. The cushioning layer516 can further include a second circumferential edge portion 524 (alsoreferred to as an outflow edge portion) located adjacent the outflow end510 of the valve, and which can form a part of the outflow protectiveportion 520. Referring still to FIG. 28, the first circumferential edgeportion 522 can comprise an edge 526, and the second circumferentialedge portion 524 can comprise an edge 528. The first circumferentialedge portion 522 can be folded or wrapped over the apices 506 of thestrut members 504 such that the edge 526 is disposed on the inside ofthe frame 502. The second circumferential edge portion 524 can be foldedaround the apices 506 at the outflow end 510 of the frame in a similarfashion such that the edge 528 is also disposed on the inside of theframe opposite the edge 522.

In the illustrated configuration, the inflow protective portion 518 caninclude a second or outer layer configured as a lubricious layer 530 ofmaterial disposed on an outer surface 532 of the main cushioning layer516. The outflow protective portion 520 can also include a second orouter lubricious layer 534 of material disposed on the outer surface 532of the main cushioning layer 516. In some embodiments, the layers 530and 534 can be smooth, low-thickness coatings comprising a low-frictionor lubricious material. For example, in certain configurations one orboth of the layers 530, 534 can comprise PTFE or ePTFE.

In the illustrated configuration, the lubricious layer 530 can have afirst circumferential edge 536 (FIG. 27) and a second circumferentialedge 538 (FIG. 28). The lubricious layer 530 can extend from the outersurface 532 of the main cushioning layer 516 and over the apices 506such that the first circumferential edge 536 is disposed on the outsideof the frame and the second circumferential edge 538 is disposed on theinside of the frame. The lubricious layer 534 can be configuredsimilarly, such that a first circumferential edge 540 (FIG. 27) isdisposed outside the frame, the layer 534 extends over the apices 506 ofthe outflow end 510 of the frame, and a second circumferential edge 542(FIG. 28) is disposed inside the frame. Once implanted in a native heartvalve, the protection portions 518 and 520 can prevent direct contactbetween the apices 506 and the surrounding anatomy. The lubriciousmaterial of the layers 530 and 534 can also reduce friction with tissueof the native valve (e.g., chordae) in contact with the inflow andoutflow ends of the prosthetic valve, thereby preventing damage to thetissue. In some embodiments, the entire outer surface 532 of the maincushioning layer 516, or a portion thereof, is covered with a lubriciouscoating such as ePTFE in addition to the inflow and outflow protectiveportions 518 and 520 such that the lubricious coating extends axiallyfrom the inflow end to the outflow end of the covering. In someembodiments, the cushioning layer 516 is formed from woven, knitted,braided, or electrospun fibers of lubricious material, such as PTFE,ePTFE, etc., and can form the inflow and outflow protective portions.

FIGS. 29-31B illustrate a representative method of making the covering514. FIG. 29 illustrates the main cushioning layer 516 formed into acylindrical, tubular body. Referring to FIG. 30, the firstcircumferential edge portion 522 of the cushioning layer 516 can then befolded over (e.g., inward toward the interior surface of the tubularbody) in the direction of arrows 544 such that the lower edge 526 isinside the tubular body and disposed against the interior surface of thetubular body. The edge portion 524 can be folded in a similar manner asindicated by arrows 546 such that the top edge 528 is inside the tubularbody and disposed against the interior surface.

Referring to FIGS. 31A and 31B, the lubricious layers 530, 534 can thenbe applied to the main layer 516 to form the inflow and outflowprotection portions 518 and 520. In certain embodiments, the lubriciouslayers 530, 534 can be formed by electrospinning a low-friction material(e.g., PTFE, ePTFE, etc.) onto the first and second circumferential edgeportions 522 and 524. In certain embodiments, forming the layers 530,and 534 by electrospinning can provide a smooth, uniform surface, andkeep the thickness of the layers within strictly prescribedspecifications.

For example, the layers 530 and 534 can be made relatively thin, whichcan reduce the overall crimp profile of the valve. In certainembodiments, a thickness of the layers 530 and 534 can be from about 10μm to about 500 μm, about 100 μm to about 500 μm, about 200 μm to about300 μm, about 200 μm, or about 300 μm. They layers 530 and 534 can bemade and/or modified in a variety of ways. In some embodiments, thelayer 530 and/or 534 is made by dip-coating, spray-coating, or any othersuitable method for applying a thin layer of lubricious material to themain cushioning layer 516. The finished covering or outer covering 514can then be situated about and secured to the frame 502 using attachmentmeans, for example, sutures, adhesive, ultrasonic welding, or any othersuitable attachment method or means. In some embodiments, the maincushioning layer 516 is situated about the frame 502 before the edgesare folded, and/or before the lubricious layers 530 and 534 are applied.In some embodiments, one or both of the lubricious layers 530 and/or 534can be omitted from the first and second circumferential edge portions522 and 524. In some embodiments, one or both of the first and secondcircumferential edge portions 522, 524 need not be folded inside theframe, but can extend to the respective inflow or outflow end of theframe, or beyond the ends of the frame on the exterior of the frame, asdesired.

In addition to covering the frame 502 and the apices 506, the outercovering 514 can provide a number of other significant advantages. Forexample, the covering 514 can be relatively thin, allowing theprosthetic valve to achieve a low crimp profile (e.g., 23 Fr or below).The one-piece, unitary construction of the outer covering 514 and theprotective portions 518 and 520 can also significantly reduce the timerequired to produce the covering and secure it to the frame, and canincrease production yield.

In some embodiments, one or both of the inflow and outflow protectionportions can be configured as separate coverings or covers that arespaced apart from the main layer or main cushioning layer, and may ormay not be coupled to the main layer or main cushioning layer. Forexample, FIGS. 32-36 illustrate an example of a prosthetic heart valve600 including a frame 602 formed by a plurality of strut members 604defining apices 606, similar to the frame 102 described above and inU.S. Pat. No. 9,393,110. The prosthetic valve 600 can have an inflow end608 and an outflow end 610, and can include a plurality of leaflets 612situated at least partially within the frame.

FIG. 34 illustrates a portion of the frame 602 in a laid-flatconfiguration for purposes of illustration. The strut members 604 can bearranged end-to-end to form a plurality of rows or rungs of strutmembers that extend circumferentially around the frame 602. For example,with reference to FIG. 34, the frame 602 can comprise a first or lowerrow I of angled strut members forming the inflow end 608 of the frame; asecond row II of strut members above the first row; a third row III ofstrut members above the second row; a fourth row IV of strut membersabove the third row, and a fifth row V of strut members above the fourthrow and forming the outflow end 610 of the frame. At the outflow end 610of the frame, the strut members 604 of the fifth row V can be arrangedat alternating angles in a zig-zag pattern. The strut members 604 of thefifth row V can be joined together at their distal ends (relative to thedirection of implantation, for example, in the mitral valve) to form theapices 606, and joined together at their proximal ends at junctions 630,which may form part of the commissure windows 638. Additional structureand characteristics of the rows I-V of strut members 604 are describedin greater detail in U.S. Pat. No. 9,393,110, incorporated by referenceabove.

Returning to FIGS. 32 and 33, the prosthetic valve can include a firstcovering or first layer 614 (also referred to as a main covering or mainlayer) situated about the frame 602. The valve can also include anoutflow protective portion configured as a second covering or cover 616disposed about the strut members 604 and the apices 606 of the fifth rowV of strut members at the outflow end 610 of the frame. The firstcovering or layer 614 can comprise a woven or knitted fabric made from,for example, PET, UHMWPE, PTFE, etc. Referring to FIG. 33, the firstcovering or layer 614 can include an inflow end portion 618 located atthe inflow end 608 of the valve, and an outflow end portion 620 locatedat the outflow end 610 of the valve. In the illustrated embodiment, theoutflow end portion 620 of the first covering or layer 614 can be offsettoward the inflow end of the frame (e.g., in the upstream direction)from the fifth row V of strut members 604. Stated differently, the strutmembers 604 of the fifth row V can extend beyond an uppermostcircumferential edge 622 of the first covering or layer 614 (e.g.,distally beyond the edge 622 when the prosthetic valve is implanted inthe native valve). A lowermost circumferential edge 624 of the maincovering or layer 614 can be disposed adjacent the first row I of strutmembers 604 at the inflow end 608 of the valve. In some embodiments, thefirst covering or layer 614 can extend over and cover the apices 606 atthe inflow end 608 of the frame.

FIG. 35 illustrates the frame 602 including the second covering or cover616 and an inner skirt 640, and without the first covering or layer 614for purposes of illustration. In certain embodiments, the secondcovering or cover 616 can be configured as a wrapping that extendsaround the circumference of the frame 602 and surrounds the fifth row Vof strut members 604. For example, with reference to FIG. 36, thecovering or cover 616 can be configured as one or more straps or strips626 of material that are helically wrapped around the struts 604 and theapices 606 of the fifth row V of strut members at the outflow end 610 ofthe frame in the direction such as indicated by arrow 632. In certainconfigurations, second covering or cover 616 is made of a lubricious orlow-friction polymeric material, such as PTFE, ePTFE, UHMWPE,polyurethane, etc. In this manner, the second covering or cover 616 canreduce friction between the second covering or cover and native tissuethat is in contact with the outflow end 610 of the valve. The coveringor cover 616 can also prevent injury to native tissue by preventing itfrom directly contacting the apices 606.

In some embodiments, the strip 626 can be relatively thick to improvethe cushioning characteristics of the second covering or cover 616. Forexample, in some embodiments, the strip 626 can be a PTFE strip having athickness of from about 0.1 mm to about 0.5 mm, and a width of fromabout 3 mm to about 10 mm. In a representative embodiment, the strip 626can have a thickness of about 0.25 mm, and a width of about 6 mm. Thesecond covering or cover 616 can also include one or multiple layers.For example, the second covering or cover 616 can include a single layer(e.g., a single strip 626) wrapped around a row of struts of the frame.The second covering or cover may also include two layers, three layers,or more of strips wrapped around a row of struts of the frame. In someembodiments, the second covering or cover 616 can comprise multiplelayers made of different materials. In certain configurations, thesecond covering or cover 616 can also be porous, and can have a poresize and pore density configured to promote tissue ingrowth into thematerial of the second covering/cover.

In some embodiments, the first covering or layer 614 and/or the secondcovering or cover 616 can be secured to the frame by attachment means,for example, suturing, adhesive, etc. In some embodiments, the first andsecond coverings 614, 616 can also be secured to each other withattachment means. For example, with reference to FIGS. 32 and 33, thefirst covering or layer 614 can include one or more sutures 628extending circumferentially around the outflow end portion 620 of thefirst covering in, for example, a running stitch. At or near thejunctions 630 (FIG. 34) of the fifth row V of strut members 604, thesuture 628 can extend out of the stitch line (e.g., from the radiallyoutward surface of the covering 614), and loop over the secondcovering/cover 616. The suture 628 can then reenter the covering 614(e.g., on the radially inward surface of the covering/layer 614) andresume the running stitch. In the illustrated embodiment, the suture 628can loop over the second covering/cover 616 at the junctions 630. Theloops of suture 628 thereby rest in “valleys” between the apices 606,and can serve to hold the second covering/cover 616 in place on thestrut members 602. The suture 628 can also hold the first covering 614in place while the valve is being crimped.

Still referring to FIGS. 32 and 33, the circumferential edge 622 of thefirst covering/layer 614 can be relatively straight, while the secondcovering/cover 616 can conform to the angled or zig-zag pattern of thefifth row V of strut members 604. In this manner, the first and secondcoverings 614 and 616 can define a plurality of gaps or openings 634through the frame 602 between the first and second coverings. In theillustrated embodiment, the openings 634 have a triangular shape, withthe base of the triangle being defined by the edge 622 of the firstcovering 614, and the sides being defined by the second covering/cover616. The openings 634 can be configured such that after the valve 600 isimplanted, blood can flow in and/or out of the frame 602 through theopenings. In this manner, the space between the interior of the frame602 and the ventricular surfaces 638 of the leaflets 612 can be flushedor washed by blood flowing into and out of the openings 634 duringoperation of the prosthetic valve. This may potentially reduce the riskof thrombus formation and left ventricular outflow tract obstruction.

FIG. 37 illustrates the frame 602 including the second covering/cover616 in a radially collapsed or crimped delivery configuration on a shaft636 of a delivery apparatus. As shown in FIG. 37, the secondcovering/cover 616 can conform to the closely-packed, serpentine shapeof the strut members 604 as they move to the radially collapsedconfiguration. In certain configurations, the second covering/cover 616can closely mimic the shape and direction of the strut members 604without bulging, pleating, creasing, or bunching to maintain a low crimpprofile. In some embodiments, the inflow end of the frame includes aseparate covering similar to the covering/cover 616.

FIGS. 38A, 38B, 39A, and 39B illustrate the prosthetic valve 400 ofFIGS. 19-26 including an example covering or outer covering 700. Theouter covering 700 can include a main layer or main cushioning layer 702having a plush exterior surface 704. The covering 700 can also includean inflow protection portion 706 extending circumferentially around theinflow end 406 of the valve, and an outflow protection portion 708extending circumferentially around the outflow end 408 of the valve. Asin the embodiment of FIGS. 19-26, the inflow and outflow protectionportions 706, 708 can be formed with separate pieces of material thatare folded around the circumferential ends of the main layer 702 suchthat the cushioning portions encapsulate the apices 420 of the strutmembers at the inflow and outflow ends of the valve. For example, theinflow and outflow protection portions 706, 708 can be constructed fromstrips of material (e.g., polymeric materials such as PTFE, ePTFE, etc.,or natural tissues such as pericardium, etc.) folded such that onecircumferential edge of the strips is disposed against the interior ofthe frame 402 (or an inner skirt within the frame), and the othercircumferential edge is disposed against the outer surface of the mainlayer 702. The outer covering 700 can be secured to the frame 402 usingattachment means, for example, sutures, ultrasonic welding, or any othersuitable attachment method or means. The layer 702 alone or togetherwith protective portions 706, 708 can form a sealing member or covermember that can be placed around the frame to form the covering 700.

The main layer 702 of the outer covering 700 can comprise a woven orknitted fabric. The fabric of the main layer 702 can be resilientlystretchable between a first, natural, or relaxed configuration (FIGS.38A and 38B), and a second, elongated, or tensioned configuration (FIGS.39A and 39B). When disposed on the frame 402, the relaxed configurationcan correspond to the radially expanded, functional configuration of theprosthetic valve, and the elongated configuration can correspond to theradially collapsed delivery configuration of the valve. Thus, withreference to FIG. 38A, the outer covering 700 can have a first length L₁when the prosthetic valve is in the expanded configuration, and a secondlength L₂ (FIG. 39A) that is longer than L₁ when the valve is crimped tothe delivery configuration, as described in greater detail below.

The fabric can comprise a plurality of circumferentially extending warpstrands/yarns 712 and a plurality of axially extending weftstrands/yarns 714. In some embodiments, the warp strands/yarns 712 canhave a denier of from about 1 D to about 300 D, about 10 D to about 200D, or about 10 D to about 100 D. In some embodiments, the warpstrands/yarns 712 can have a thickness t₁ (FIG. 40A) of from about 0.01mm to about 0.5 mm, about 0.02 mm to about 0.3 mm, or about 0.03 mm toabout 0.1 mm. In some embodiments, the warp strands/yarns 712 can have athickness t₁ of about 0.03 mm, about 0.04 mm, about 0.05 mm, about 0.06mm, about 0.07 mm, about 0.08 mm, about 0.09 mm, or about 0.1 mm. In arepresentative embodiment, the warp strands/yarns 712 can have athickness of about 0.06 mm.

The weft strands/yarns 714 can be texturized strands/yarns comprising aplurality of texturized filaments 716. For example, the filaments 716 ofthe weft strands/yarns 714 can be bulked, wherein, for example, thefilaments 716 are twisted, heat set, and untwisted such that thefilaments retain their deformed, twisted shape in the relaxed,non-stretched configuration. The filaments 716 can also be texturized bycrimping, coiling, etc. When the weft strands/yarns 714 are in arelaxed, non-tensioned state, the filaments 716 can be loosely packedand can provide compressible volume or bulk to the fabric, as well as aplush surface. In some embodiments, the weft strands/yarns 714 can havea denier of from about 1 D to about 500 D, about 10 D to about 400 D,about 20 D to about 350 D, about 20 D to about 300 D, or about 40 D toabout 200 D. In certain embodiments, the weft strands/yarns 714 can havea denier of about 150 D. In some embodiments, a filament count of theweft strands/yarns 714 can be from 2 filaments per strand/yarn to 200filaments per strand/yarn, 10 filaments per strand/yarn to 100 filamentsper strand/yarn, 20 filaments per strand/yarn to 80 filaments perstrand/yarn, or about 30 filaments per strand/yarn to 60 filaments peryarn. Additionally, although the axially-extending texturedstrands/yarns 714 are referred to as weft strands/yarns in theillustrated configuration, the fabric may also be manufactured such thatthe axially-extending textured strands/yarns are warp strands/yarns andthe circumferentially-extending strands/yarns are weft strands/yarns.

FIGS. 40A and 40B illustrate a cross-sectional view of the main layer702 in which the weft strands/yarns 712 extend into the plane of thepage. With reference to FIG. 40A, the fabric of the main layer 702 canhave a thickness t₂ of from about 0.1 mm to about 10 mm, about 1 mm toabout 8 mm, about 1 mm to about 5 mm, about 1 mm to about 3 mm, about0.5 mm, about 1 mm, about 1.5 mm, about 2 mm, about 2.5 mm, or about 3mm when in a relaxed state and secured to a frame. In some embodiments,the main layer 702 can have a thickness of about 0.1 mm, about 0.2 mm,about 0.3 mm, about 0.4 mm, or about 0.5 mm as measured in a relaxedstate with a weighted drop gauge having a presser foot. In arepresentative example, the main layer 702 can have a thickness of about1.5 mm when secured to a prosthetic valve frame in the relaxed state.This can allow the fabric of the main layer 702 to cushion the leafletsbetween the valve body and an anchor or ring into which the valve isimplanted, as well as to occupy voids or space in the anatomy. Thetexturized, loosely packed filaments 716 of the weft strands/yarns 714in the relaxed state can also promote tissue growth into the main layer702.

When the fabric is in the relaxed state, the textured filaments 716 ofthe weft strands/yarns 714 can be widely dispersed such that individualweft strands/yarns are not readily discerned, as in FIGS. 38A and 38B.When tensioned, the filaments 716 of the weft strands/yarns 714 can bedrawn together as the weft strands/yarns elongate and the kinks, twists,etc., of the filaments are pulled straight such that the fabric isstretched and the thickness decreases. In certain embodiments, whensufficient tension is applied to the fabric in the axial (e.g., weft)direction, such as when the prosthetic valve is crimped onto a deliveryshaft, the textured fibers 716 can be pulled together such thatindividual weft strands/yarns 714 become discernable, as best shown inFIGS. 39B and 40B.

Thus, for example, when fully stretched, the main layer 702 can have asecond thickness t₃, as shown in FIG. 40B that is less than thethickness t₂. In certain embodiments, the thickness of the tensionedweft strands/yarns 714 may be the same or nearly the same as thethickness t₁ of the warp strands/yarns 712. Thus, in certain examples,when stretched the fabric can have a thickness t₃ that is the same ornearly the same as three times the thickness t₁ of the warpstrands/yarns 712 depending upon, for example, the amount of flatteningof the weft strands/yarns 714. Accordingly, in the example above inwhich the warp strands/yarns 712 have a thickness of about 0.06 mm, thethickness of the main layer 702 can vary between about 0.2 mm and about1.5 mm as the fabric stretches and relaxes. Stated differently, thethickness of the fabric can vary by 750% or more as the fabric stretchesand relaxes.

Additionally, as shown in FIG. 40A, the warp strands/yarns 712 can bespaced apart from each other in the fabric by a distance y₁ when theouter covering is in a relaxed state. As shown in FIGS. 39B and 40B,when tension is applied to the fabric in the direction perpendicular tothe warp strands/yarns 712 and parallel to the weft strands/yarns 714,the distance between the warp strands/yarns 712 can increase as the weftstrands/yarns 714 lengthen. In the example illustrated in FIG. 40B, inwhich the fabric has been stretched such that the weft strands/yarns 714have lengthened and narrowed to approximately the diameter of the warpstrands/yarns 712, the distance between the warp strands/yarns 712 canincrease to a new distance y₂ that is greater than the distance y₁.

In certain embodiments, the distance y₁ can be, for example, about 1 mmto about 10 mm, about 2 mm to about 8 mm, or about 3 mm to about 5 mm.In a representative example, the distance y₁ can be about 3 mm. In someembodiments, when the fabric is stretched as in FIGS. 39B and 40B, thedistance y₂ can be about 6 mm to about 10 mm. Thus, in certainembodiments, the length of the outer covering 700 can vary by 100% ormore between the relaxed length L₁ and the fully stretched length (e.g.,L₂). The fabric's ability to lengthen in this manner can allow theprosthetic valve to be crimped to diameters of, for example, 23 Fr,without being limited by the outer covering's ability to stretch. Thus,the outer covering 700 can be soft and voluminous when the prostheticvalve is expanded to its functional size, and relatively thin when theprosthetic valve is crimped to minimize the overall crimp profile of theprosthetic valve.

FIGS. 41A, 41B, 42A, and 42B show an example of a sealing member orcover member 800 for a prosthetic heart valve (e.g., such as theprosthetic heart valve 400). The sealing member 800 can be a dual-layerfabric comprising a base layer 802 and a pile layer 804. FIG. 41A showsthe outer surface of the sealing member 800 defined by the pile layer804. FIG. 42A shows the inner surface of the sealing member 800 definedby the base layer 802. The base layer 802 in the illustratedconfiguration comprises a mesh weave having circumferentially extendingrows or stripes 806 of higher-density mesh portions interspersed withrows or stripes 808 of lower-density mesh portions. The sealingmember/cover member 800 can be used to cover or form a covering on astent frame (e.g. on some, a portion, or all of a stent frame).

In some embodiments, the strand/yarn count of strands/yarns extending inthe circumferential direction (side-to-side or horizontally in FIGS. 42Aand 42B) is greater in the higher-density rows 806 than in thelower-density rows 808. In some embodiments, the strand/yarn count ofstrands/yarns extending in the circumferential direction and thestrand/yarn count of strands/yarns extending in the axial direction(vertically in FIGS. 42A and 42B) is greater in the higher-density rows806 than in the lower-density rows 808.

The pile layer 804 can be formed from strands/yarns woven into the baselayer 802. For example, the pile layer 804 can comprise a velour weaveformed from strands/yarns incorporated in the base layer 802. Referringto FIG. 41B, the pile layer 804 can comprise circumferentially extendingrows or stripes 810 of pile formed at axially-spaced locations along theheight of the sealing member 800 such that there are axial extendinggaps between adjacent rows 810. In this manner, the density of the pilelayer varies along the height of the sealing member. In someembodiments, the pile layer 804 can be formed without gaps betweenadjacent rows of pile, but the pile layer can comprise circumferentiallyextending rows or stripes of higher-density pile interspersed with rowsor stripes of lower-density pile.

In some embodiments, the base layer 802 can comprise a uniform meshweave (the density of the weave pattern is uniform) and the pile layer804 has a varying density.

In some embodiments, the density of the sealing member 800 can varyalong the circumference of the sealing member. For example, the pilelayer 804 can comprise a plurality of axially-extending,circumferentially-spaced, rows of pile yarns, or can comprisealternating axially-extending rows of higher-density pile interspersedwith axially-extending rows of lower-density pile. Similarly, the baselayer 802 can comprise a plurality axially-extending rows ofhigher-density mesh interspersed with rows of lower-density mesh.

In some embodiments, the sealing member 800 includes a base layer 802and/or a pile layer 804 that varies in density along the circumferenceof the sealing member and along the height of the sealing member.

Varying the density of the pile layer 804 and/or the base layer 802along the height and/or the circumference of the sealing member 800 isadvantageous in that it reduces the bulkiness of the sealing member inthe radially collapsed state and therefore reduces the overall crimpprofile of the prosthetic heart valve.

In certain embodiments, the outer covering 800 can include inflow and/oroutflow protective portions similar to the protective portions 416 and418 above. However, in some embodiments, the outer covering 800 need notinclude protective portions and can extend between the top and bottomrow of strut members of a frame, or between intermediate rows of strutmembers, depending upon the particular application.

FIGS. 43 and 44 illustrate a prosthetic heart valve 900 including anexample of a covering or outer covering 902 situated around a frame 904,and including a plurality of leaflets 922 (FIG. 44) situated at leastpartially within the frame 904. The frame 904 can include a plurality ofstruts 920, and can be configured as the frame of the EdwardsLifesciences SAPIEN® 3 prosthetic heart valve, similar to the frame 402of FIG. 19. The outer covering 902 can include a main cushioning layeror sealing member/cover member 906 (also referred to as a main layer)having a cylindrical shape, and made from a woven, knitted, or braidedfabric (e.g., a PET fabric, an ultra-high molecular weight polyethylene(UHMWPE) fabric, a PTFE fabric, etc.), a non-woven fabric such as felt,or an extruded polymer film (e.g., an ePTFE or UHMWPE membrane). Theouter covering 902 can also include an inflow protection portion 908extending circumferentially around the inflow end 910 of the frame, andan outflow protection portion 912 extending circumferentially around theoutflow end 914 of the frame. In the embodiment of FIGS. 43 and 44, theinflow and outflow protection portions 908 and 912 are configured asseparate pieces of material folded around the circumferential ends ofthe main layer 906 similar to the embodiment of FIGS. 19-26, but mayalso comprise lubricous layers formed on the circumferential edgeportions of the main layer 906 by other means, such as byelectrospinning, as in the embodiment of FIG. 31A.

Referring to FIG. 43, the layer 906 of the outer covering 902 cancomprise a woven or knitted fabric. The layer 906 can comprise aplurality of holes or openings 916 circumferentially spaced apart fromeach other around the frame 904, and aligned with or overlying openingsdefined between the frame struts. For example, in the illustratedembodiment the openings 916 can be located at the level of openings 918defined between the frame struts 920 of the fourth row IV and the fifthrow V of struts (see also FIG. 34) near the outflow end 914 of theframe. The openings 916 can be relatively small, as in the embodiment ofFIG. 43, or larger, depending upon the particular characteristicsdesired.

For example, with reference to FIG. 44, in certain embodiments theopenings 916 can be the same size and shape, or nearly the same size andshape, as the frame openings 918. Thus, in the embodiment of FIG. 44,the openings 916 can comprise the polygonal (e.g., hexagonal) shape ofthe frame openings 918, and can be of the same size or area as the frameopenings 918. In this configuration, relatively narrow strips 930 of themain layer 906 can extend along axially-oriented struts 920A between thefourth row IV and the fifth row V of struts, and over the commissurewindows and the commissure tabs 932 of the leaflets 922. Thus, incertain configurations, the openings 916 of the covering 902 can bealigned with the frame openings 918, and yet the covering 902 can coverthe entire outer surface of the frame 904. In other words, the covering902 can cover the outer surfaces of all of the strut members 920.

The openings 916 can be formed in a variety of ways. In certainembodiments, the openings 916 are cut (e.g., using a laser) from thefabric of the main layer 906 before the covering is assembled on theframe 904. In some embodiments, the covering 902 comprises two separateouter or main layers spaced apart axially from each other on the frame904, with one layer extending between, for example, the first row I ofstruts 920 and the fourth row IV of struts, and the other layerextending along the fifth row V such that the frame openings 918 areuncovered. The openings 916 of the main layer 906 can have any size orshape, can be located at any location along the axis of the prostheticvalve, and/or at different axial locations. The openings 916 can alsohave any suitable circumferential spacing.

FIG. 45 illustrates an example of the prosthetic valve 900 in which themain layer 906 (which can form part or all of a sealing member or covermember) of the outer covering 902 comprises a first portion 924including a plush (e.g., knitted) pile layer 928 similar to the covering414 of FIG. 19, and a second portion 926 without a pile. Additionalportions are also possible. The plush pile layer 928 of the firstportion 924 can extend circumferentially around the frame 904, andaxially along the frame 904 from the inflow end portion 910 to the levelof the fourth row IV of struts 920. The second portion 926 can define aplurality of round openings 916 positioned over the frame openings 918,and having an area smaller than the frame openings 918, although theopenings 916 can have any size, shape, location, and/or spacing. Thepile layer 928 can be configured to extend along any portion of the axisof the prosthetic valve.

In certain embodiments, the first portion 924 and the second portion 926comprise different pieces of material. For example, in some embodiments,the first portion 924 is a knitted fabric comprising the plush pilelayer 928 described above, and the second portion 926 is a knittedfabric without a pile layer. The first and second portions 924, 926 canbe configured to overlap each other (e.g., a portion of the firstportion 924 may extend over the second portion 926 where the two piecesof fabric meet). The second portion 926 can also have a different knitpattern than the first portion 924, and can also comprise strands (e.g.,yarns, etc.) having different properties (e.g., denier, material,surface characteristics such as texturing, number of filaments, numberof plies, number of twists, etc.) from the strands/yarns of the firstportion 924. In some embodiments the first portion 924 and/or the secondportion 926 comprise knit patterns formed using a two bar system, athree bar system, a four bar system, etc., or as many as an eight barsystem. The first portion 924 and/or the second portion 926 can beknitted in a variety of ways, e.g., using a circular technique, acrochet technique, a tricot technique, a raschel technique, othertechniques, or combinations thereof. The properties of the secondportion 926 can be optimized to allow the openings 916 to be createdmore easily (e.g., by laser cutting), and to ensure that the fabricretains its structural integrity. For example, cloth or fabric made ofcertain types of woven strands or woven yarns may be more likely to fallapart and/or fray if openings are cut therein, so the second portion 926could be made of a bias cloth or bias fabric that is less likely to fallapart or fray when openings are cut therein. Optionally, the first andsecond portions 924, 926 can comprise a single piece of fabric. In someembodiments, the first portion 924 and/or the second portion 926comprise a non-woven material (e.g., foam, felt, etc.).

Including openings such as the openings 916 in the outer covering 902may promote blood flow through the covering from the interior of theprosthetic valve to the exterior such that the struts 920 and theradially-outward surfaces of the leaflets 922 are bathed or washed byblood flowing through the prosthetic valve during valve operation. Thismay help to reduce blood stasis around the strut members 920, andbetween the struts 920 and the leaflets 922, which may potentiallyreduce the risk of thrombosis.

FIGS. 46-51 show an example of a main cushioning layer or sealingmember/cover member 1000. The sealing member 1000 can comprise a fabricbody having a plurality of different portions working together, such asa plurality first portions (e.g., woven portions, multiple sets of wovenportions, etc.) and a plurality of second portions (e.g., elastic,stretchable portions configured as floating portions, such as floatingyarn portions), which can be incorporated into any of the prostheticvalve outer coverings described herein. FIG. 46 illustrates the sealingmember/cover member 1000 in a laid-flat configuration where the x-axiscorresponds to the circumferential direction and the y-axis correspondsto the axial direction when the sealing member is attached to a frame ofa prosthetic valve. The sealing member 1000 can comprise a plurality offirst portions (such as first woven portions 1002 configured as wovenstrips or stripes extending along the x-axis), a plurality of secondportions (such as second woven portions 1004 configured as woven stripsor stripes extending along the x-axis), a plurality of third portions(e.g., floating portions or floating yarn portions, strips, or stripes1006 extending along the x-axis), and/or optionally additional portions.The various woven and floating portions/floating yarn portions can bespaced apart from each other along the y-axis. In the illustratedconfiguration, the first woven portions 1002 comprise a weave patternthat is different from the weave pattern of the second woven portions1004, as described in greater detail below.

In one example configuration, as illustrated, the sealing member/covermember 1000 comprises a first woven portion 1002A, which can be at thelower or inflow edge of the sealing member/cover member. Moving in adirection along the positive y-axis, the sealing member/cover member1000 can further comprise a second woven portion 1004A, a floatingportion/floating yarn portion 1006A, a second woven portion 1004B, afloating portion/floating yarn portion 1006B, a second woven portion1004C, a floating portion/floating yarn portion 1006C, a second wovenportion 1004D, a floating portion/floating yarn portion 1006D, a secondwoven portion 1004E, a first woven portion 1002B, a second woven portion1004F, a floating portion/floating yarn portion 1006E, a second wovenportion 1004G, and a first woven portion 1002C at the opposite end ofthe sealing member/cover member from the first woven portion 1002A. Inother words, the first woven portion 1002B and each of the floatingportions/floating yarn portions 1006A-1006E can be located between twosecond woven portions 1004 such that the first woven portion 1002B andeach of the floating portion/floating yarn portions 1006A-1006E arebounded or edged in a direction along the x-axis by respective secondwoven portions 1004.

Referring to FIGS. 47 and 48, the main layer or sealing member/covermember 1000 can comprise a plurality of first strands 1008 (e.g., yarns,etc.) oriented generally along the x-axis and a plurality of secondyarns 1010 oriented generally along the y-axis. In certainconfigurations, the first strands/yarns 1008 are warp strands/yarns,meaning that during the weaving process the strands/yarns 1008 are heldby the loom, while the second strands/yarns 1010 are weft strands/yarns,which are interwoven with the warp strands/yarns by a moving shuttle orweft-carrying mechanism during the weaving process. However, in someembodiments the first strands/yarns 1008 can be weft strands/yarns andthe second strands/yarns 1010 can be warp strands/yarns.

Each of the first strands/yarns 1008 and the second strands/yarns 1010can comprise a plurality of constituent filaments 1012 that are spun,wound, twisted, intermingled, interlaced, etc., together to form therespective strands/yarns. Exemplary individual filaments 1012 of thesecond strands/yarns 1010 can be seen in FIGS. 48-50. In someembodiments, the first strands/yarns 1008 have a denier of from about 1D to about 200 D, about 10 D to about 100 D, about 10 D to about 80 D,about 10 D to about 60 D, or about 10 D to about 50 D. In someembodiments, the first strands/yarns 1008 have a filament count of 1 toabout 600 filaments per strand/yarn, about 10 to about 300 filaments perstrand/yarn, about 10 to about 100 filaments per strand/yarn, about 10to about 60 filaments per strand/yarn, about 10 to about 50 filamentsper strand/yarn, or about 10 to about 30 filaments per yarn. In someembodiments, the first strands/yarns 1008 have a denier of about 40 Dand a filament count of 24 filaments per yarn. The first strands/yarns1008 can also be twisted strands/yarns or non-twisted strands/yarns. Inthe illustrated embodiment, the filaments 1012 of the firststrands/yarns 1008 are not texturized. However, in some embodiments, thefirst strands/yarns 1008 can comprise texturized filaments.

The second strands/yarns 1010 can be texturized strands/yarns comprisinga plurality of texturized filaments 1012. For example, the filaments1012 of the second strands/yarns 1010 can be texturized, for example, bytwisting the filaments, heat-setting them, and untwisting the filamentsas described above. In some embodiments, the second strands/yarns 1010have a denier of from about 1 D to about 200 D, about 10 D to about 100D, about 10 D to about 80 D, or about 10 D to about 70 D. In someembodiments, a filament count of the second strands/yarns 1010 isbetween 1 filament per strand/yarn to about 100 filaments perstrand/yarn, about 10 to about 80 filaments per strand/yarn, about 10 toabout 60 filaments per strand/yarn, or about 10 to about 50 filamentsper yarn. In some embodiments, the second strands/yarns 1010 have adenier of about 68 D and a filament count of about 36 filaments peryarn.

The first strands/yarns 1008 and the second strands/yarns 1010 can bewoven together to form the woven portions of the sealing member/covermember, as noted above. For example, in the first woven portions1002A-1002C, the first and second strands/yarns 1008, 1010 can be woventogether in a plain weave pattern in which the second strands/yarns 1010(e.g., the weft strands/yarns) pass over a first strand/yarn 1008 (e.g.,a warp yarn) and then under the next first strand/yarn in a repeatingpattern. This weave pattern is illustrated in detail in FIG. 47. In someembodiments, the density of the first strands/yarns 1008 is from about10 strands/yarns per inch to about 200 strands/yarns per inch, about 50strands/yarns per inch to about 200 strands/yarns per inch, or about 100strands/yarns per inch to about 200 strands/yarns per inch. In certainembodiments, the first woven portion 1002A and the first woven portion1002C can be configured as selvedge (selvage) portions, and can have alower strand/yarn density than the first woven portion 1002B tofacilitate assembly on a valve frame. Other weave patterns can also beused, such as over two under two, over two under one, etc. The firstwoven portions can also be woven in plain weave derivative patterns suchas twill, satin, or combinations of any of these.

In the second woven portions 1004A-1004G, the first and secondstrands/yarns 1008, 1010 can be interwoven in another pattern that isdifferent from the weave pattern of the first woven portions1002A-1002C. For example, in the illustrated embodiment, the first andsecond strands/yarns 1008, 1010 are woven together in a leno weavepattern in the second woven portions 1004A-1004G. FIG. 48 illustratesthe leno weave of the second woven portion 1004B in greater detail. Withreference to FIG. 48, the leno weave can comprise one or more lenostrands/yarns or “leno ends” 1014, and four first strands/yarns 1008A,1008B, 1008C, and 1008D, also referred to as “warp ends.” The patternillustrated in FIG. 48 includes a single leno strand/yarn 1014 in themanner of a half-leno weave. However, in some embodiments, the lenoweave pattern can be a full-leno weave comprising two intertwining lenostrands/yarns 1014, or other leno-derived weaves. Examples of half-lenoweaves, full-leno weaves, and associated weaving techniques areillustrated in FIGS. 55A-55J.

In the half-leno weave illustrated in FIG. 48, the first strands/yarns1008A-1008D can extend parallel to the x-axis, and the secondstrands/yarns 1010 can be interwoven with the first strands/yarns1008A-1008D in, for example, a plain weave. The leno strand/yarn 1014can weave around the first strands/yarns 1008A-1008D such that the lenostrand/yarn 1014 crosses over, or on top of, the first strands/yarns1008A-1008D with each pass in the positive y-direction, crosses beneathor behind the next second yarn 1010 in the x-direction, and extends backover the first strands/yarns 1008A-1008D in the negative y-direction.This pattern can be repeated along the length of the second wovenportion 1004B. In this manner, the second woven portions 1004 can berelatively narrow, strong woven portions spaced axially from each otheralong the frame when the sealing element is mounted to a frame. The lenostrand/yarn 1014 can serve to keep the first strands/yarns 1008A-1008Dand the second strands/yarns 1010 in place with respect to each other asthe prosthetic valve is crimped and expanded, and can impart strength tothe second woven portions 1004 while minimizing width.

In certain embodiments, each of the second woven portions 1004A-1004Gcomprise the leno weave pattern described above. In some embodiments,one or more of the second woven portions 1004A-1004G is configureddifferently, such as by incorporating more or fewer first strands/yarns1008 in the leno weave, having multiple leno ends woven around multiplegroupings of strands/yarns 1008, etc. In some embodiments, a chemicallocking method is used where the leno weave and/or a plain weaveincludes warp strands/yarns having core-sheath construction filaments.The sheath of the individual filaments can be made of low-melttemperature polymers such as biocompatible polypropylene, and the coreof the filaments be made of another biocompatible polymer such aspolyester. After the weaving process, the heat setting process describedbelow can enable the softening and/or melting of the sheath. Uponcooling, the softened sheath polymer can bond the core polyesterfilaments together. This can create a bonded body enabling locking ofthe woven structure.

Referring again to FIG. 46, the floating portions or floating yarnportions 1006 can comprise strands/yarns extending in only one axisbetween respective second woven portions 1004 that are spaced apart fromeach other along the y-axis. For example, taking the floatingportion/floating yarn portion 1006A as a representative example, thefloating portion/floating yarn portion 1006A can comprise a plurality ofsecond strands/yarns 1010 that exit the leno weave of the second wovenportion 1004A, extend across the floating portion/floating yarn portion1006A, and are incorporated into the leno weave of the second wovenportion 1004B without being interwoven with any other strands/yarns inthe floating portion/floating yarn portion. In some embodiments, thedensity of the second strands/yarns in the floating portion/floatingyarn portions 1006 is from about 10 to about 200 strands/yarns per inch,about 50 to about 200 strands/yarns per inch, or about 100 to about 200strands/yarns per inch. In some embodiments, the density of the secondstrands/yarns 1010 is about 60-80 strands/yarns per inch. In someembodiments, the floating portions/floating yarn portions include firststrands/yarns 1008 disposed under or over, but not interwoven with, thesecond strands/yarns 1010 such that the second strands/yarns float overthe first strands/yarns or vice versa. The floating portions or floatingyarn portions can also be configured as any other elasticallystretchable structure, such as elastically stretchable woven, knitted,braided, or non-woven fabrics, or polymeric membranes, to name a few,that is elastically stretchable at least in the axial direction of theprosthetic valve.

In the illustrated embodiment, each of the woven portions 1002A-1002Cand 1004A-1004G, and each of the floating portions 1006A-1006E havewidth dimensions in the y-axis direction. The widths of the constituentportions can be configured such that the overall length L₁ (FIG. 46) ofthe sealing member/cover member 1000 generally corresponds to the axiallength of a prosthetic heart valve in the expanded configuration. Forexample, in the illustrated embodiment the first woven portions 1002Aand 1002C each have a width W₁. In certain embodiments, the width W₁ isconfigured such that portions of the first woven portions 1002A and1002C can be folded over the respective inflow and/or outflow ends ofthe frame of a prosthetic valve.

The first woven portion 1002B can have a width W₂. With reference toFIG. 52, when the sealing member/cover member 1000 is used incombination with the frame of the Edwards Lifesciences SAPIEN® 3prosthetic heart valve, the width W₂ can be configured to correspond tothe axial dimension of the frame openings defined by the strut membersbetween the fourth row IV and the fifth row V of struts, as described ingreater detail below. In some embodiments, the width W₂ of the firstwoven portion 1002B is about 2 mm to about 20 mm, about 2 mm to about 12mm, or about 3 mm to about 10 mm. In some embodiments, the width W₂ isabout 7 mm.

The second woven portions 1004A-1004G can have widths W₃ (FIG. 48). Inthe illustrated embodiment, all of the second woven portions 1004A-1004Ghave the width W₃, but one or more of the second woven portions can alsohave different widths. In certain embodiments, the width W₃ can berelatively short, such as about 0.1 mm to about 3 mm, about 0.1 mm toabout 2 mm, or about 0.1 mm to about 1 mm. In some embodiments, thewidth W₃ is about 1 mm.

With reference to FIGS. 46 and 49-52, in certain embodiments, thesealing member/cover member 1000, and in particular the floatingportions/floating yarn portions 1006A-1006E, are resiliently stretchablebetween a first, natural, or relaxed configuration (FIGS. 46 and FIG.49) corresponding to the radially expanded state of the prostheticvalve, and a second, elongated, or tensioned configuration (FIGS. 50 and51) corresponding to the radially compressed state of the prostheticvalve. Thus, the floating portions 1006A-1006E can have initial widthsW₄ when the sealing member 1000 is in the relaxed, unstretched state.FIG. 49 illustrates a portion of the floating portion 1006B in thenatural, relaxed state. When the fabric is in the relaxed state, thetextured filaments 1012 of the second strands/yarns 1010 can be kinkedand twisted in many directions such that the floating portion 1006B hasa bulky, billowy, or pillow-like quality, and provides a compressiblevolume or bulk. When tensioned, the kinks, twists, etc., of thefilaments 1012 can be pulled at least partially straight along they-axis, causing the second strands/yarns 1010 to elongate. Withreference to FIG. 50, the width of the floating portions 1006 can thusincrease to a second width W₅ that is larger than the initial width W₄.

The cumulative effect of the floating portions/floating yarn portions1006A-1006E increasing in width from the initial width W₄ to the secondwidth W₅ is that the overall axial dimension of the sealing member/covermember 1000 can increase from the initial length L₁ (FIG. 46) to asecond overall length L₂ (FIG. 51) that is greater than the first lengthL₁. FIG. 51 illustrates the sealing member 1000 in the stretchedconfiguration with the second strands/yarns 1010 of the floating yarnportions 1006A-1006E straightened under tension such that the overalllength of the sealing member increases to the second length L₂. Incertain embodiments, the size, number, spacing, etc., of the floatingyarn portions 1006, and the degree of texturing of the constituentsecond strands/yarns 1010, can be selected such that the second lengthL₂ of the sealing member 1000 corresponds to the length of a frame of aprosthetic valve when the prosthetic valve is crimped for delivery on adelivery apparatus, as described below with reference to FIGS. 53 and54. In some embodiments, the relaxed initial width W₄ of the floatingyarn portions 1006 is about 1 mm to about 10 mm, about 1 mm to about 8mm, or about 1 mm to about 5 mm. In some embodiments, the initial widthW₄ is about 4 mm.

FIG. 52 illustrates an edge portion of the sealing member/cover member1000 gripped between a pair of grippers 1050. In certain embodiments,the bulky, billowy nature of the texturized strands/yarns 1010 in thefloating portions/floating yarn portions 1006 results in the floatingportions/floating yarn portions 1006 having a thickness t₁ that isgreater than a thickness t₂ of the woven portions 1002 and 1004. Forexample, in certain embodiments the thickness t₁ of the floatingportions 1006 is two times, three times, four times, five times, sixtimes, or even ten times greater than the thickness t₂ of the wovenportions 1002 and 1004, or more, when the sealing member is in therelaxed state. This can allow the floating portions 1006 to cushion thenative leaflets between the valve body and/or against an anchor or ringinto which the prosthetic valve is implanted. The floating portions 1006can also occupy voids or space in the anatomy, and/or promote tissuegrowth into the floating portions, as in the embodiments describedabove. When tension is applied to stretch the floating portions 1006,the thickness t₁ can decrease as the texturized second strands/yarns1010 straighten. In certain embodiments, the thickness t₁ is equal ornearly equal to the thickness t₂ of the woven portions 1002 and 1004when the sealing member is in the tensioned state. When the tension onthe sealing member 1000 is released, such as during expansion of theprosthetic valve, the strands/yarns 1012 can resume their texturizedshape and the thickness of the floating portions 1006 can return to theinitial thickness t₁.

FIG. 53 illustrates the sealing member 1000 formed into an outercovering 1018 and assembled onto the frame 1020 of a prosthetic valve1022. In the illustrated embodiment, the frame 1020 is the frame of theEdwards Lifesciences SAPIEN® 3 prosthetic heart valve similar to theframes described above, although the sealing member 1000 can beconfigured for use on other prosthetic valves as well, including theframe in FIG. 56. The outer covering 1018 can also include an inflowprotection portion 1024 and an outflow protection portion 1026 similarto the outer coverings described above, and can be configured forimplantation in a native valve, such as the mitral valve, tricuspidvalve, aortic valve, pulmonary valve, Eustachian valve, etc., althoughin some embodiments the outer covering need not include the inflowand/or the outflow protection portions, and can be configured forimplantation in other heart valves or body lumens as well. The sealingmember 1000 can be oriented such that the second woven portions1004A-1004G and the floating portions/floating yarn portions 1006A-1006Eextend circumferentially around the frame 1020, and such that thefloating portion/floating yarn portion 1006A is adjacent the inflowprotection portion 1024 at the inflow end of the prosthetic valve. Inthis configuration, the texturized second strands/yarns 1010 extend in adirection along the longitudinal axis 1034 of the prosthetic valve. Inthe illustrated embodiment, the first woven portion 1002A and the secondwoven portion 1004A can be disposed at least partially beneath theinflow protection portion 1024 and are not visible in the figure.Similarly, the first woven portion 1002C and the second woven portion1004G can be disposed at least partially beneath the outflow protectionportion 1026 and are also not visible in the figure.

Still referring to FIG. 53, the outer covering 1018 can be secured tothe frame by attachment means, for example, suturing, adhering, etc.,the sealing member 1000 to the frame 1020 along one or more of thesecond woven portions 1004A-1004G. The first woven portion 1002B canalso comprise a plurality of circumferentially spaced-apart openings1016. The openings 1016 can be sized and positioned to overliecorresponding openings defined by the frame struts between the fourthrow IV of struts and the fifth row V of struts, similar to theembodiment of FIG. 43 above. In some embodiments, the sealing member1000 is incorporated into an outer covering in the state illustrated inFIG. 46 without openings in the first woven portion 1002B.

FIG. 54 illustrates the prosthetic valve 1022 crimped for delivery on aballoon 1028 at the distal end of a balloon catheter 1030 of a deliveryapparatus 1032. Further details of representative delivery systems thatcan be used with the prosthetic valves described herein can be found inU.S. Publication No. 2017/0065415 and U.S. Pat. No. 9,339,384, which areincorporated herein by reference. As shown in the example illustrated inFIG. 53, the floating portions/floating yarn portions 1006A-1006E areelongated and the texturized second strands/yarns 1010 are at leastpartially straightened, allowing the sealing member 1000 to lengthen toaccommodate the increased length of the crimped frame 1020. In certainembodiments, the floating portions/floating yarn portions 1006A-1006Eare configured such that the sealing member 1000 can elongate by about10% to about 500%, about 10% to about 300%, about 10% to about 200%,about 10% to about 100%, about 10% to about 80%, or about 10% to about50%. In some embodiments, the floating portions/floating yarn portions1006A-1006E are configured to allow the sealing member 1000 to elongateby about 30%, corresponding to the elongation of the frame 1022 betweenthe expanded and crimped configurations. As noted above, the increase inwidth of the floating portions/floating yarn portions 1006A-1006E canalso result in a corresponding decrease in thickness of the floatingportions/floating yarn portions, reducing the crimp profile of theprosthetic valve during delivery.

In some embodiments, the first and second strands/yarns 1008 and 1010can comprise any of various biocompatible thermoplastic polymers such asPET, Nylon, ePTFE, UHMWPE, etc., or other suitable natural or syntheticfibers. In certain embodiments, the sealing member 1000 can be woven ona loom, and can then be heat-treated or heat-set to achieve the desiredsize and configuration. For example, depending upon the materialselected, heat-setting can cause the sealing member 1000 to shrink.Heat-setting can also cause a texturizing effect, or increase the amountof texturizing, of the second strands/yarns 1010. After heat treatment,the openings 1016 can be created in the first woven portion 1002B (e.g.,by laser cutting), and the sealing member can be incorporated intoand/or form an outer covering such as the covering 1018 for assemblyonto a prosthetic valve. In some embodiments, the openings 1016 can alsobe created before heat treatment.

In certain embodiments, the loops, filaments, floating portions,floating yarn portions, etc., of the prosthetic sealing membersdescribed herein can be configured to promote a biological response inorder to form a seal between the prosthetic valve and the surroundinganatomy. In certain configurations, the sealing members described hereincan be configured to form a seal over a selected period of time. Forexample, in certain embodiments, the open, porous nature of the loops,filaments, strands/yarns, etc., can allow a selected amount ofparavalvular leakage around the prosthetic valve in the time periodfollowing implantation. The amount of paravalvular leakage past the sealstructure may be gradually reduced over a selected period of time as thebiological response to the loops, filaments, strands/yarns, etc., causesblood clotting, tissue ingrowth, etc. In some embodiments, the sealingmembers, and in particular the loops, filaments, strands/yarns, etc., ofthe paravalvular sealing structure, are treated with one or more agentsthat inhibit the biological response to the sealing structures. Forexample, in certain embodiments, the loops, filaments, strands/yarns,etc., are treated with heparin. In certain embodiments, the amount orconcentration of the agent(s) is selected such that the agents aredepleted after a selected period of time (e.g., days, weeks, or months)after valve implantation. As the agent(s) are depleted, the biologicalresponse to the loops, filaments, strands, yarns, etc., of the sealingstructures may increase such that a paravalvular seal forms graduallyover a selected period of time. This may be advantageous in patientssuffering from heart remodeling, such as left atrial or left ventricularremodeling (e.g., due to mitral regurgitation, etc.), by providing anopportunity for the remodeling to reverse as regurgitation past theprosthetic valve is gradually reduced.

FIGS. 55A-55J illustrate various leno weaves and leno weaving techniquesthat can be used to produce the sealing member/cover member 1000, or anyof the other sealing members/cover members described herein. FIG. 55A isa cross-sectional view illustrating a shed (e.g., the temporaryseparation of warp strands/yarns to form upper and lower warpstrands/yarns) in which a leno yarn, “leno end,” or “crossing end” 1060forms the top shed on the left of the figure above a weft strand/yarn1064 and a standard warp strand/yarn 1062 forms the bottom shed. FIG.55B illustrates a successive shed in which the leno strand/yarn 1060forms the top shed on the right of the standard warp strand/yarn 1062.In FIGS. 55A and 55B, the leno strand/yarn 1060 can cross under thestandard strand/yarn 1062 in a pattern known as bottom douping.Alternatively, the leno strand/yarn 1060 can cross over the standardstrand/yarn 1062, known as top douping, as in FIGS. 55H and 55I.

FIG. 55C illustrates a leno weave interlacing pattern produced when onewarp beam is used on a loom, and the distortion or tension of the lenostrands/yarns 1060 and the standard strands/yarns 1062 is equal suchthat both the strands/yarns 1060 and the strands/yarns 1062 curve aroundthe weft strands/yarns 1064. FIG. 55D illustrates a leno weave lacingpattern produced when multiple warp beams are used, and the lenostrands/yarns 1060 are less tensioned than the standard strands/yarns1062 such that the standard strands/yarns 1062 remain relativelystraight in the weave, and perpendicular to the weft strands/yarns 1064,while the leno strands/yarns 1060 curve around the standardstrands/yarns 1062.

FIG. 55E illustrates an interlacing pattern corresponding to FIG. 55C,but in which alternate leno strands/yarns 1060 are point-drafted (e.g.,a technique in which the leno strands/yarns are drawn through heddles)such that adjacent leno strands/yarns 1060 have opposite lacingdirections. FIG. 55F illustrates an interlacing pattern corresponding toFIG. 55D, but in which the leno strands/yarns 1060 are point-draftedsuch that adjacent leno strands/yarns have opposite lacing directions.

FIG. 55G is a cross-sectional view of a plain leno weave structure takenthrough the weft strands/yarns 1064.

FIG. 55J illustrates a representative leno weave as viewed from thereverse side of the fabric.

The prosthetic valve covering embodiments described herein can also beused on a variety of different types of prosthetic heart valves. Forexample, the coverings can be adapted, and in some embodiments areadapted, for use on mechanically-expandable prosthetic heart valves,such as the valve 1100 illustrated in FIG. 56. The prosthetic valve 1100can include an annular stent or frame 1102, and a leaflet structure 1104situated within and coupled to the frame 1102. The frame 1102 caninclude an inflow end 1106 and an outflow end 1108. The leafletstructure can comprise a plurality of leaflets 1110, such as threeleaflets arranged to collapse in a tricuspid arrangement similar to theaortic valve such that the leaflets form commissures 1132 whererespective outflow edge portions 1134 of the leaflets contact eachother. Optionally, the prosthetic valve can include two leaflets 1110configured to collapse in a bicuspid arrangement similar to the mitralvalve, or more than three leaflets, depending upon the particularapplication.

With reference to FIG. 56, the frame 1102 can include a plurality ofinterconnected lattice struts 1112 arranged in a lattice-type patternand forming a plurality of apices 1114 at the outflow end 1108 of theprosthetic valve. The struts 1112 can also form similar apices 1114 atthe inflow end 1106 of the prosthetic valve. The lattice struts 1112 canbe pivotably coupled to one another by hinges 1116 located where thestruts overlap each other, and also at the apices 1114. The hinges 1116can allow the struts 1112 to pivot relative to one another as the frame1102 is expanded or contracted, such as during assembly, preparation, orimplantation of the prosthetic valve 1100. The hinges 1116 can compriserivets or pins that extend through apertures formed in the struts 1112at the locations where the struts overlap each other. In the embodimentof FIG. 56, the struts 1112 include apertures for five hinges 1116.However, the struts may include any number of hinges depending upon theparticular size of the frame, etc. For example, in some embodiments thestruts comprise seven hinges, as in the configuration shown in FIG. 57.Additional details regarding the frame 1102 and devices and techniquesfor radially expanding and collapsing the frame can be found in U.S.Publication No. 2018/0153689, which is incorporated herein by reference.

As illustrated in FIG. 56, the frame 1102 can comprise a plurality ofactuator components 1118 that can also function as release-and-lockingunits (also referred to as locking assemblies) configured to radiallyexpand and contract the frame. In the illustrated configuration, theframe 1102 comprises three actuator components 1118 configured as postsand coupled to the frame 1102 at circumferentially spaced locations,although the frame can include more or fewer actuator componentsdepending upon the particular application. Each of the actuatorcomponents 1118 generally can comprise an inner member 1120, such as aninner tubular member, and an outer member 1122, such as an outer tubularmember concentrically disposed about the inner member 1120. The innermembers 1120 and the outer members 1122 can be moveable longitudinallyrelative to each other in a telescoping manner to radially expand andcontract the frame 1102, as further described in U.S. Publication No.2018/0153689.

In the illustrated configuration, the inner members 1120 have distal endportions 1124 coupled to the inflow end 1106 of the frame 1102 (e.g.,with a coupling element such as a pin member). In the illustratedembodiment, each of the inner members 1120 are coupled to the frame atrespective apices 1114 at the inflow end 1106 of the frame. The outermembers 1122 can be coupled to apices 1114 at the outflow end 1108 ofthe frame 1102 at, for example, a mid-portion of the outer member, asshown in FIG. 56, or at a proximal end portion of the outer member, asdesired.

The inner member 1120 and the outer member 1122 can telescope relativeto each other between a fully contracted state (corresponding to a fullyradially expanded state of the prosthetic valve) and a fully extendedstate (corresponding to a fully radially compressed state of theprosthetic valve). In the fully extended state, the inner member 1120 isfully extended from the outer member 1122. In this manner, the actuatorcomponents 1118 allow the prosthetic valve to be fully expanded orpartially expanded to different diameters and retain the prostheticvalve in the partially or fully expanded state.

In some embodiments, the actuator components 1118 are screw actuatorsconfigured to radially expand and compress the frame 1102 by rotation ofone of the components of the actuators. For example, the inner members1120 can be configured as screws having external threads that engageinternal threads of corresponding outer components. Further detailsregarding screw actuators are disclosed in U.S. Publication No.2018/0153689.

The prosthetic valve 1100 can also include a plurality of commissuresupport elements configured as commissure clasps or clamps 1136. In theillustrated configuration, the prosthetic valve includes a commissureclamp 1136 positioned at each commissure 1132 and configured to grip theleaflets 1110 of the commissure at a location spaced radially inwardlyof the frame 1102. Further details regarding commissure clamps aredisclosed in U.S. Publication No. 2018/0325665, which is incorporatedherein by reference.

FIG. 57 illustrates an example of a mechanically-expandable frame 1202with components such as the leaflets, leaflet clamps, and actuatorcomponents removed for purposes of illustration. The frame 1202 can besimilar to the frame 1102, except that the struts 1204 include sevenapertures 1206 spaced apart along the length of each strut for forminghinges similar to the hinges 1116. For example, each strut 1204 caninclude a plurality of round, curved, or circular portions 1212connected by straight portions or segments 1214. Each successive segment1214 can be parallel to, but circumferentially offset from, thepreceding segment 1214, as described in U.S. Publication No.2018/0153689. Each round portion 1212 can define an aperture 1206. Thus,taking the strut member 1204A by way of example, the round portion 1212Aat the inflow end 1208 of the frame 1202 can define an aperture 1206A.Moving along the strut 1204A in the direction of the outflow end 1210,the portion 1212B can define an aperture 1206B, the portion 1212C candefine an aperture 1206C, the portion 1212D can define an aperture1206D, the portion 1212E can define an aperture 1206E, the portion 1212Fcan define an aperture 1206F, and the portion 1212G can define anaperture 1206G at the outflow end 1210. The apertures, and the hingesformed therewith, can function substantially as described above to allowthe frame to be radially collapsed for delivery and radially expanded atthe treatment site.

In the illustrated configuration, the struts 1204 are arranged in twosets, with the first set being on the inside of the frame 1202, offsetcircumferentially from each other, and angled such that the strutsextend helically around the central axis 1216 of the frame. In theembodiment of FIG. 57, struts 1204B and 1204C are part of the first orinner set of struts. The second set of struts 1204 can be disposedradially outward of the first set of struts. The second set of strutscan be angled such that the apertures 1206 align with the apertures 1206of the inner set of struts, and can be oriented with the oppositehelicity as the first set of struts. In the embodiment illustrated inFIG. 57, the struts 1204A and 1204D are part of the second or outer setof struts. The inner and outer sets of struts 1204 can form inflowapices 1218 of the frame where the respective round portions 1212 align,and can form outflow apices 1220 where the respective round portions atthe opposite ends of the struts align. In the expanded configuration,the struts 1204 of the inner and outer sets of struts can also define aplurality of diamond-shaped cells or openings 1222.

FIGS. 58 and 59 illustrate an example of a main cushioning layer, covermember, or sealing member 1300. The sealing member 1300 can comprise afabric body having a plurality of woven portions and one or morefloating portions (e.g., floating yarn portions, etc.), similar to theembodiment of FIG. 46. FIG. 58 illustrates the sealing member 1300 in alaid-flat configuration where the x-axis corresponds to thecircumferential direction and the y-axis corresponds to the axialdirection when the sealing member 1300 is attached to a prosthetic valveframe. FIG. 59 is a magnified view of a portion of the sealing member1300. Beginning at the inflow end portion 1310 of the sealing member1300, the sealing member can comprise a first woven portion 1302A.Moving in a direction along the positive y-axis, the sealing member 1300can further comprise a second woven portion 1304A, a floatingportion/floating yarn portion 1306, a second woven portion 1304B, and afirst woven portion 1302B. The first woven portion 1302B is located atthe outflow end portion 1312 on the opposite side of the floatingportion/floating yarn portion from the first woven portion 1302A.

Still referring to FIG. 59, the sealing member 1300 can comprisestrands/yarns 1308 extending in the x-direction (e.g., warpstrands/yarns) and strands/yarns 1314 extending in the y-direction(e.g., weft strands/yarns), as in the examples above. In certainembodiments, at least the strands/yarns 1314 can be texturized. Thetexturized strands/yarns 1314 can be interwoven with the strands/yarns1308 in the first woven portion 1302A, and in the second woven portion1304A. The texturized strands/yarns 1314 can extend or “float” across tothe second woven portion 1304B to form the floating portions/floatingyarn portion 1306. The strands/yarns 1314 can reenter the weave at thesecond woven portion 1304B.

As in the embodiment of FIG. 46, the first woven portions 1302A and1302B can comprise a plain weave. In some embodiments, the first wovenportion 1302A and/or the first woven portion 1302B can have astrand/yarn density of from 20 strands/yarns (or ends) per inch to 150strands/yarns per inch, such as 40 strands/yarns per inch to 120strands/yarns per inch. In some embodiments, first woven portions 1302Aand 1302B can be configured as selvedges, and can prevent the fabricfrom unraveling.

The second woven portion 1304A can extend along the lower edge of thefloating portion/floating yarn portion 1306, and second woven portion1304B can extend along the upper edge of the floating portion/floatingyarn portion 1306. In this manner, the floating portion/floating yarnportion 1306 can be bounded or edged in a direction along the x-axis bythe second woven portions 1304A and 1304B. In some configurations, thewidths of the second woven portions 1304A and 1304B can be relativelysmall in comparison to the first woven portions 1302A and 1302B, similarto the embodiment of FIG. 46. In some embodiments, the second wovenportions 1304A and 1304B comprises a leno weave pattern, such as any ofthe leno weave patterns described above. For example, with reference tothe example in FIG. 59, each of the second woven portions 1304A and1304B comprise two leno ends 1316 intertwined around strands/yarns 1314and strands/yarns 1308, and may be top-douped or bottom-douped. In someembodiments, the second woven portions 1304A and 1304B comprise one lenoend, or more than two leno ends.

The sealing member 1300 can be resiliently stretchable between a first,natural width corresponding to a non-tensioned state, and a second widthwhen the sealing member is stretched in the y-direction, similar to theembodiment of FIG. 46. As in the previously described embodiments, thetexturized strands/yarns 1314 of the floating portion/floating yarnportion 1306 can be configured to be provide a bulky, compressiblevolume when in the relaxed state. When the sealing member 1300 istensioned in the y-direction, the texturized strands/yarns 1314 can bepulled straight, causing the sealing member to lengthen in they-direction.

FIG. 60 illustrates the sealing member or cover member 1300 secured tothe frame 1202 of FIG. 57 to form a covering on the frame. In FIG. 60,the frame is in the expanded configuration and the covering and thesealing member are in the first, relatively non-tensioned state. In theillustrated embodiment, the first woven portion 1302A can be secured(e.g., by attachment means, such as suturing, adhesive, etc.) to theinflow end portions of the struts 1204. For example, with reference toFIG. 61, the first woven portion 1302A can be folded over the inflowapices 1218 so that the free edge 1318 of the fabric is located insidethe frame 1202, and so that the first woven portion 1302A covers theapices 1218.

Referring to the outer struts 1204A and 1204D of FIG. 60, the firstwoven portion 1302B can be sized so that it extends from approximatelythe level of the round portions 1212C to the round portions 1212D. Incertain embodiments, the first woven portion 1302B can be shaped tomatch the shape of the cells 1222 (FIG. 57) formed by the struts 1204when the frame 1202 is in the expanded configuration. For example, thefirst woven portion 1302B can be cut or shaped such that it comprises aplurality of extension portions 1320. The extension portions 1320 can besized to correspond to portions of the cells 1222 that extend above thesecond woven portion 1304B. In the illustrated embodiment, the extensionportions 1320 are tapered in the direction of flow through the valvesuch that they have a trapezoidal shape, such as an isoscelestrapezoidal shape. However, the extension portions 1320 can have anyother shape, such as a triangular shape, a rectangular shape, etc. Theextension portions 1320 can be sutured to the frame 1202 along the strutsegments 1214 (FIG. 57) extending between the round portions 1212C and1212D of the struts on the outer diameter of the frame, and to thecorresponding segments of the struts 1204 on the inside of the frame.

With reference to the outer set of struts 1204, the floatingportion/floating yarn portion 1306 can extend between about the level ofthe round portions 1212B to the round portions 1212C. When the frame1202 is in the expanded configuration, the floating portion/floatingyarn portion 1306 can extend or bulge radially outwardly from the frameto form a voluminous, compressible, pillow-like structure or cushion,which can aid in sealing against the surrounding anatomy. The texturizedstrands/yarns of the floating portion/floating yarn portion 1306 canalso provide a porous environment for tissue ingrowth.

Still referring to FIG. 60, when the frame 1202 is in the expandedconfiguration, the frame can have a length L₁. The covering and thesealing member 1300 can have a corresponding length H₁, which can bemeasured from the inflow apices 1218 to the upper or outflow-most edge1322 of the extension portions 1320. As illustrated in FIG. 62, when theframe 1202 is radially collapsed for delivery, the length of the framecan increase to a second length L₂. As the frame lengthens, the coveringand the sealing member 1300, and the floating portion/floating yarnportion 1306 in particular, can also stretch such that the covering andthe sealing member lengthen to a second length H₂ (e.g., correspondingto a second, tensioned state) to accommodate the increased length of theframe 1202. In some embodiments, the frame 1202 is configured tolengthen by 10% to 160% or more between the expanded configuration andthe collapsed configuration. Thus, the covering and the sealing member1300 can also be configured to stretch by a similar amount, such as from10% to 200%, 10% to 180%, 10% to 160%, etc., in order to accommodate thelength change of the frame.

Although the prosthetic valve covering embodiments described herein aresometimes presented in the context of mitral valve repair, it should beunderstood that the disclosed coverings can be used in combination withany of various prosthetic heart valves for implantation at any of thenative valves in or around the heart. For example, the prosthetic valvecoverings described herein can be used in combination with transcatheterheart valves, surgical heart valves, minimally-invasive heart valves,etc. The covering embodiments herein can be used in prosthetic valvesintended for implantation at any of the native valve of an animal orpatient (e.g., the aortic, pulmonary, mitral, tricuspid, and Eustachianvalve, etc.), and include valves that are intended for implantationwithin existing prosthetics valves (so called “valve-in-valve”procedures). The covering embodiments can also be used in combinationwith other types of devices implantable within other body lumens outsideof the heart, or heart valves that are implantable within the heart atlocations other than the native valves, such as trans-atrial ortrans-ventricle septum valves.

General Considerations

For purposes of this description, certain aspects, advantages, and novelfeatures of the embodiments of this disclosure are described herein. Thedisclosed methods, apparatus, and systems should not be construed asbeing limiting in any way. Instead, the present disclosure is directedtoward all novel and nonobvious features and aspects of the variousdisclosed embodiments, alone and in various combinations andsub-combinations with one another. The methods, apparatus, and systemsare not limited to any specific aspect or feature or combinationthereof, nor do the disclosed embodiments require that any one or morespecific advantages be present or problems be solved.

Although the operations of some of the disclosed embodiments aredescribed in a particular, sequential order for convenient presentation,it should be understood that this manner of description encompassesrearrangement, unless a particular ordering is required by specificlanguage set forth below. For example, operations described sequentiallymay in some cases be rearranged or performed concurrently. Moreover, forthe sake of simplicity, the attached figures may not show the variousways in which the disclosed methods can be used in conjunction withother methods. Additionally, the description sometimes uses terms like“provide” or “achieve” to describe the disclosed methods. These termsare high-level abstractions of the actual operations that are performed.The actual operations that correspond to these terms may vary dependingon the particular implementation and are readily discernible by one ofordinary skill in the art.

As used in this application and in the claims, the singular forms “a,”“an,” and “the” include the plural forms unless the context clearlydictates otherwise. Additionally, the term “includes” means “comprises.”Further, the terms “coupled” and “associated” generally meanelectrically, electromagnetically, and/or physically (e.g., mechanicallyor chemically) coupled or linked and does not exclude the presence ofintermediate elements between the coupled or associated items absentspecific contrary language.

In the context of the present application, the terms “lower” and “upper”are used interchangeably with the terms “inflow” and “outflow”,respectively. Thus, for example, the lower end of the valve is itsinflow end and the upper end of the valve is its outflow end.

As used herein, the term “proximal” refers to a position, direction, orportion of a device that is closer to the user and further away from theimplantation site. As used herein, the term “distal” refers to aposition, direction, or portion of a device that is further away fromthe user and closer to the implantation site. Thus, for example,proximal motion of a device is motion of the device toward the user,while distal motion of the device is motion of the device away from theuser. The terms “longitudinal” and “axial” refer to an axis extending inthe proximal and distal directions, unless otherwise expressly defined.

In view of the many possible embodiments to which the principles of thedisclosed technology may be applied, it should be recognized that theillustrated embodiments are only preferred examples and should not betaken as limiting the scope of the disclosure. Rather, the scope of thedisclosure is at least as broad as the following claims.

The invention claimed is:
 1. A prosthetic heart valve, comprising: aframe comprising a plurality of strut members, the frame being radiallycollapsible and expandable between a collapsed configuration and anexpanded configuration, the frame having an inflow end and an outflowend, and defining a longitudinal axis; a leaflet structure situated atleast partially within the frame; and a covering disposed around theframe, the covering comprising: a first woven portion extendingcircumferentially around the frame, the first woven portion comprising aplurality of texturized strands extending along the longitudinal axis ofthe frame; a second woven portion extending circumferentially around theframe and spaced apart from the first woven portion along thelongitudinal axis of the frame; wherein the texturized strands extendalong the longitudinal axis of the frame from the first woven portion tothe second woven portion and form a floating portion between the firstwoven portion and the second woven portion.
 2. The prosthetic heartvalve of claim 1, wherein the covering is resiliently stretchablebetween a first state corresponding to the radially expandedconfiguration of the frame, and a second state corresponding to theradially collapsed configuration of the frame.
 3. The prosthetic heartvalve of claim 2, wherein the floating portion is resilientlystretchable between the first state and the second state of thecovering.
 4. The prosthetic heart valve of claim 1, wherein thetexturized strands are configured to provide compressible volume to thefloating portion of the covering when the frame is in the expandedconfiguration.
 5. The prosthetic heart valve of claim 1, wherein thetexturized strands are woven into a leno weave pattern in the firstwoven portion and in the second woven portion.
 6. The prosthetic heartvalve of claim 1, wherein the covering defines a plurality ofcircumferentially spaced-apart openings.
 7. The prosthetic heart valveof claim 6, wherein the openings in the covering overlie openingsdefined by strut members of the frame.
 8. The prosthetic heart valve ofclaim 6, wherein the openings have been cut into a portion of thecovering made of a bias cloth to inhibit fraying around the openings. 9.The prosthetic heart valve of claim 1, wherein the covering furthercomprises a third woven portion on the opposite side of the first wovenportion from the floating portion, the third woven portion comprisingthe texturized strands of the first woven portion.
 10. The prostheticheart valve of claim 9, wherein the texturized strands are woven into aplain weave pattern in the third woven portion.
 11. The prosthetic heartvalve of claim 9, wherein the third woven portion is folded over apicesof strut members at the inflow end of the frame.
 12. The prostheticheart valve of claim 9, wherein: the covering further comprises a fourthwoven portion on the opposite side of the second woven portion from thefloating portion; and the fourth woven portion comprises the texturizedstrands, and the texturized strands are woven into a plain weave patternin the fourth woven portion.
 13. The prosthetic heart valve of claim 12,wherein the fourth woven portion comprises a plurality of extensionportions that overlie openings defined by the strut members of the framewhen the frame is in the expanded configuration.
 14. The prostheticheart valve of claim 13, wherein the extension portions are tapered in adirection toward the outflow end of the frame.
 15. The prosthetic heartvalve of claim 1, wherein the frame is at least one of amechanically-expandable frame and a plastically-expandable frame. 16.The prosthetic heart valve of claim 1, wherein the covering comprises aplurality of floating portions spaced apart from each other along thelongitudinal axis of the frame.
 17. The prosthetic heart valve of claim1, wherein the floating portions are heat set to make them softer and/ormore texturized.
 18. The prosthetic heart valve of claim 1, whereintwisted PET strands are used in a warp direction and textured PETstrands are used in a weft direction.
 19. The prosthetic heart valve ofclaim 18, wherein the twisted PET strands in the warp direction arearranged to weave in leno pattern and the textured PET strands in theweft direction form the floating portion without any weave structure.20. The prosthetic heart valve of claim 19, wherein the coverings isheat shrunk to achieve a stretchability between 80-160% and wherein theframe is a mechanically-expandable frame.
 21. The prosthetic heart valveof claim 1, wherein the covering comprises at least one of alow-friction layer or low-friction coating on a least a portion thereof.22. The prosthetic heart valve of claim 21, wherein the low-frictionlayer or low-friction coating is formed via electrospinning.
 23. Theprosthetic heart valve of claim 1, further comprising strips of materialthat are helically wrapped around struts and apices at an end of theframe.
 24. The prosthetic heart valve of claim 1, wherein: the coveringcomprises a first protective portion folded over apices of the strutmembers at the inflow end of the frame; and the covering furthercomprises a second protective portion folded over apices of the strutmembers at the outflow end of the frame.